taxonID	type	description	language	source
7F707B9048AD57E680653950D4D9487C.taxon	diagnosis	Diagnosis. Chamaecostus manausensis sp. nov. (Fig. 1) looks quite similar to C. congestiflorus and has been regularly confused with that species but can be distinguished by a narrowly cylindric (instead of broadly obovoid) inflorescence and a non-fimbriate labellum.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
7F707B9048AD57E680653950D4D9487C.taxon	materials_examined	Type. Brazil. Amazonas: Maua Road, 22 Mar 1971, Prance, Coelho, Kubitzki & Maas 11529 (holotype: U 2 sheets: U 1219716 & U 1219717; isotypes: BR, COL 128233, CR, DAV, E, F 175333, F 1842269, GH, INPA, K, MO, NY, P, S, US, VEN, W).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
7F707B9048AD57E680653950D4D9487C.taxon	description	Description. Herb 0.4 - 1 m tall. Leaves sheaths 2 - 15 mm diam; ligule 1 - 2 mm long; petiole 0 - 5 mm long; sheaths, ligule and petiole densely puberulous; lamina 13 - 25 x 3 - 6 cm, narrowly elliptic, adaxially sparsely puberulous to glabrous, abaxially sometimes reddish-purple, sparsely to densely puberulous, particularly the primary vein, base obtuse, apex acuminate, acumen 5 - 15 mm long. Inflorescence 4 - 10 x 1.5 - 3 cm, up to ca. 13 x 4 cm in fruit, narrowly cylindric, terminating a leafy shoot; bracts, bracteoles, calyx, ovary, and capsule rather densely to densely puberulous; bracts 2.5 - 3.5 x 0.3 - 0.5 cm, narrowly triangular, green, chartaceous, apex often mucronate, callus 3 - 6 mm long; bracteole 15 - 20 mm long, tubular, often deeply split on the abaxial side, 2 - lobed, lobes 3 - 7 mm long, deltate. Flowers calyx 20 - 33 mm long, green, tube often deeply split during anthesis, lobes 5 - 10 mm long, subulate; corolla 50 - 65 mm long, cream, densely puberulous, lobes 30 - 40 mm long narrowly, obovate; labellum ca. 35 x 40 mm, cream, distal edge horizontally spreading, broadly angular-obovate, margin crenulate; stamen 25 - 30 x 10 mm, cream, apex reflexed, irregularly dentate, anther 5 - 6 mm long. Capsules 11 - 13 mm long, ellipsoid.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
7F707B9048AD57E680653950D4D9487C.taxon	distribution	Distribution. Brazil (Amazonas, Para) (Fig. 21 A).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
7F707B9048AD57E680653950D4D9487C.taxon	etymology	Etymology. This species is named " manausensis " after the city of Manaus, State of Amazonas, Brazil, where this species is most commonly distributed.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
9C3F9D551EA1561D9D8D56211BEDCC2A.taxon	diagnosis	Diagnosis. Costus alfredoi sp. nov. (Fig. 2) is recognizable by an extremely small ligule (<1 mm long), a " basal " inflorescence (inflorescence terminates a short, leafless shoot and thus is positioned at the base of the plant) with red, unappendaged bracts and yellow, tubular flowers, an almost complete lack of indument, and very narrow, grass-like leaves. It shares the last two features with C. vargasii but differs by a shorter ligule (<1 mm vs. 5 - 35 mm long) and a much longer calyx (15 - 16 vs. 6 - 10 mm) and bracteole (25 - 27 vs. 12 - 22 mm).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
9C3F9D551EA1561D9D8D56211BEDCC2A.taxon	materials_examined	Type. Bolivia, La Paz: Prov. Bautista Saavedra, Area Natural de Manejo Integrado Apolobamba, between Paujeyuyo and Calzada, 1140 m, 16 Nov 2003, Fuentes Claros, Cayola, Whitehead & Cuevas 6216 (holotype: MO 2098346; isotypes: U 1212213 & U 1212214).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
9C3F9D551EA1561D9D8D56211BEDCC2A.taxon	description	Description. Herb ca. 2 m tall. Leaves sheaths 4 - 5 mm diam; ligule obliquely truncate, <1 mm long; petiole 5 - 7 mm long; sheaths, ligule and petiole glabrous; lamina linear, 15 - 23 x 1.5 - 2.5 cm, adaxially and abaxially glabrous, except for some hairs along the margin, base acute to obtuse, apex long-acute. Inflorescence ovoid, 11 - 12 x 5 - 6 cm, terminating a leafless shoot 50 - 85 cm long, sheaths obliquely truncate, 6 - 8 cm long, glabrous; bracts, bracteole, calyx, ovary, and capsule glabrous; bracts red, coriaceous, ovate, 3 - 4 x 1.5 - 2.5 cm, apex obtuse, callus 5 - 7 mm long; bracteole boat-shaped, 25 - 27 mm long. Flowers abaxially oriented; calyx 15 - 16 mm long, lobes shallowly ovate-triangular, 2 - 3 mm long; corolla yellow to orange, ca. 50 mm long, glabrous, lobes narrowly elliptic, ca. 30 mm long; labellum yellow, lateral lobes rolled inwards and forming a curved tube ca. 10 mm diam, oblong-elliptic when spread out, ca. 35 x 15 mm, middle lobe with yellow honey mark, 5 - 7 - lobulate, lobules red, 5 - 6 mm long; stamen yellow, ca. 35 x 7 mm, slightly exceeding the labellum, apex red, slightly dentate, anther length not measured. Capsule ellipsoid, ca. 15 mm long.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
9C3F9D551EA1561D9D8D56211BEDCC2A.taxon	distribution	Distribution. Bolivia (La Paz) (Fig. 21 B).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
9C3F9D551EA1561D9D8D56211BEDCC2A.taxon	etymology	Etymology. Costus alfredoi is named after the very active and inspiring Bolivian plant collector Alfredo Fuentes, who we personally met some years ago during a visit to the MO Herbarium and who provided us with additional data on Bolivian species of Costaceae.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
09336D8339175178B7FE6E7E4AC55868.taxon	diagnosis	Diagnosis. Costus alleniopsis sp. nov. (Fig. 3) resembles C. allenii but differs by distinctly plicate leaves and a longer ligule.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
09336D8339175178B7FE6E7E4AC55868.taxon	materials_examined	Type. Panama, Veraguas: Rio Segundo Brazo, 700 - 750 m, 8 Sep 1974, Maas & Dressler 1652 (holotype U 1231561; isotypes F, MO- 2193025).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
09336D8339175178B7FE6E7E4AC55868.taxon	description	Description. Herb 0.5 - 1.2 m tall. Leaves sheaths 10 - 20 mm diam; ligule obliquely truncate, 12 - 20 mm long, often reddish; petiole 10 - 25 mm long; sheaths, ligule and petiole densely brownish villose; lamina ovate to obovate, 25 - 32 by 13 - 16 cm, abaxially sometimes reddish, 10 - 12 - plicate, adaxially and abaxially densely brownish villose, base cordate, acute, or obtuse, apex acuminate (acumen 10 - 15 mm long). Inflorescence ovoid, 6 - 7 x 3 - 5 cm, terminating a leafy shoot or rarely terminating a leafless shoot; bracts rather densely to densely brownish villose, bracteole, calyx, ovary, and capsule rather densely to densely puberulous to glabrous. Flowers adaxially oriented to erect; bracts green, rarely red, coriaceous, broadly ovate to ovate, 3 - 5 x 2 - 5 cm, apex obtuse, callus 5 - 7 mm long; bracteole boat-shaped, 20 - 30 mm long; calyx pink to red, 8 - 10 mm long, lobes shallowly triangular, 2 - 3 mm long; corolla yellow, 60 - 70 mm long, glabrous, lobes narrowly elliptic, 50 - 60 mm long; labellum yellow, distal edge horizontally spreading, broadly obovate, 50 - 70 x 40 - 50 mm, lateral lobes striped with red, middle lobe reflexed, with yellow honey mark, margin crenulate; stamen yellow, 40 - 50 x 12 - 15 mm, not exceeding the labellum, apex red, obtuse to irregularly dentate, anther 7 - 10 mm long. Capsule ellipsoid, 15 - 20 mm long.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
09336D8339175178B7FE6E7E4AC55868.taxon	distribution	Distribution. Panama (Cocle, Colon, Veraguas) (Fig. 21 C).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
09336D8339175178B7FE6E7E4AC55868.taxon	etymology	Etymology. This species strongly resembles C. allenii, and the Greek word " opsis " (= likeness) refers to the resemblance with that species.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
5B398AFCE2A95824B19C58E6A19DE6EB.taxon	diagnosis	Diagnosis. Costus alticolus sp. nov. (Fig. 4) can be recognised by its leafless flowering shoots up to ca. 1 m long, combined with large, red and unappendaged bracts, tubular and yellow flowers, and stamen far exceeding the labellum like in C. pulverulentus C. Presl.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
5B398AFCE2A95824B19C58E6A19DE6EB.taxon	materials_examined	Type. Mexico. Oaxaca: Sierra Mazateca, Mun. Santa Maria Chilchotla, Cuauhtemoc, ca. 4 km NE of Santa Maria Chilchotla, near Clemencia and Santa Rosa, 1200 m, 16 Jan 1984, Solheim & Reisfeld 1367 (holotype WIS).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
5B398AFCE2A95824B19C58E6A19DE6EB.taxon	description	Description. Herb 2 - 3.5 m tall. Leaves sheaths 10 - 30 mm diam; ligule truncate, 4 - 12 mm long; petiole 5 - 20 mm long; sheaths, ligule and petiole densely to sparsely puberulous; lamina narrowly elliptic, 25 - 47 x 6 - 14 cm, adaxially glabrous, abaxially densely (particularly along the primary vein) sericeous to almost glabrous, base acute, apex acuminate (acumen 5 - 10 mm long). Inflorescence cylindric, 11 - 18 x 5 - 9 cm, terminating a leafless shoot 20 - 95 cm long, sheaths obliquely truncate, 4 - 7 cm long, rather densely puberulous to glabrous; bracts, bracteole, calyx, ovary, and capsule glabrous to densely puberulous. Flowers abaxially oriented; bracts red to bright crimson, coriaceous, ovate-oblong, 4 - 6 x 3 - 4 cm, apex obtuse, callus ca. 10 mm long; bracteole boat-shaped, 30 - 35 mm long; calyx red, 13 - 21 mm long, lobes deltate to shallowly triangular, 3 - 6 mm long; corolla yellow to orange, 50 - 60 mm long, glabrous, lobes narrowly elliptic, ca. 40 mm long; labellum yellow, lateral lobes rolled inwards and forming a slightly curved tube 18 - 20 mm diam, obovate when spread out, ca. 60 by 35 mm, irregularly lobulate, lobules recurved, ca. 4 mm long; stamen yellow, ca. 65 x 11 mm, far exceeding the labellum, apex acute, anther ca. 8 mm long. Capsule ellipsoid, 17 - 18 mm long.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
5B398AFCE2A95824B19C58E6A19DE6EB.taxon	distribution	Distribution. Mexico (Oaxaca) (Fig. 21 D).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
5B398AFCE2A95824B19C58E6A19DE6EB.taxon	etymology	Etymology. Costus alticolus sp. nov. occurs at quite high elevations up to 1900 m, hence the specific epithet alticolus (' altus' means ' high' in Latin; ' colere' means ' to live' in Latin).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
6C2E39521D7D51B4910820D0CCE6FA23.taxon	diagnosis	Diagnosis. Costus antioquiensis sp. nov. (Figs 5, 6) is well recognisable by adaxially oriented flowers, an often present ring of brown, erect and rather stiff hairs at the base of the ligule, and the abaxial leaf lamina and the bracts being often densely villose. It could be confused with Costus laevis Ruiz & Pav., but that species has much darker flowers and is often completely glabrous.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
6C2E39521D7D51B4910820D0CCE6FA23.taxon	materials_examined	Type. Colombia, Antioquia: Mun. San Rafael, along road from Guatape to San Rafael, Rio El Bizcocho, Finca El Castillo, 1059 m, 12 Oct 2013, Maas, Maas-van de Kamer & Valderrama 10488 (holotype L, 3 sheets; isotypes JAUM, K, MO- 3159234, MO- 3159235).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
6C2E39521D7D51B4910820D0CCE6FA23.taxon	description	Description. Herb 0.5 - 5 m tall. Leaves sheaths 10 - 20 mm diam; ligule truncate, 5 - 10 mm long, basally densely covered with a ring of brown, erect and rather stiff hairs (villose), sometimes absent; petiole 5 - 20 mm long; sheaths and petiole sparsely or sometimes densely villose; lamina narrowly elliptic, 30 - 50 x 9 - 13 cm, adaxially glabrous, sometimes densely villose, abaxially densely to sometimes sparsely villose or glabrous, base obtuse, apex acuminate (acumen 5 - 10 mm long). Inflorescence ovoid, 8 - 16 x 5 - 6 cm, enlarging to ca. 25 by 7 - 8 cm in fruit, terminating a leafy shoot; bracts, bracteoles, calyx, ovary, and capsule densely puberulous to villose, rarely glabrous. Flowers adaxially oriented to erect; bracts green, coriaceous, broadly ovate, 3 - 4 x 3 - 4 cm, apex obtuse, callus 8 - 10 mm long; appendages rarely present; bracteole boat-shaped, 20 - 27 mm long; calyx (pale) red, 7 - 11 mm long, lobes deltate to shallowly triangular, ca. 3 mm long; corolla yellow, pale orange, or pink, 60 - 70 mm long, glabrous, lobes elliptic, 40 - 60 mm long; labellum yellowish white, distal edge horizontally spreading, broadly obovate, 50 - 70 x 40 - 60 mm, lateral lobes striped with red, middle lobe reflexed, with dark yellow honey mark, margin irregularly dentate; stamen yellowish white to pink, ca. 40 x 10 - 12 mm, not exceeding the labellum, apex dark red, entire to dentate, anther ca. 8 mm long. Capsule obovoid, 25 - 28 mm long.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
6C2E39521D7D51B4910820D0CCE6FA23.taxon	distribution	Distribution. Colombia (Amazonas, Antioquia, Arauca, Boyaca, Caldas, Cauca, Choco, Cordoba, Cundinamarca, Guajira, Guaviare, Huila, Meta, Norte de Santander, Quindio, Risaralda, Santander, Tolima, Valle del Cauca, Vichada), Venezuela (Merida), Ecuador (Azuay, Carchi, Pastaza, Zamora-Chinchipe), Peru (Ucayali). (Fig. 21 E)	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
6C2E39521D7D51B4910820D0CCE6FA23.taxon	etymology	Etymology. This species was collected by Paul and Hiltje Maas for the first time in the Colombian department of Antioquia and is therefore named in recognition of that locality.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
A7EA1648C6B85EB68D92DD79EA7064BF.taxon	diagnosis	Diagnosis. Costus callosus sp. nov. (Fig. 7) is most similar to C. curvibracteatus, differing by the inflorescence mostly produced terminally on a leafless shoot, with soon withering sheaths and bracts with a very long callus.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
A7EA1648C6B85EB68D92DD79EA7064BF.taxon	materials_examined	Type. Colombia, Choco: Mun. San Jose del Palmar, mouth of Rio Torito (affluent of Rio Habita), Finca Los Guaduales, 730 - 830 m, 4 Mar 1980, E. Forero, Jaramillo-Mejia, Espina Z. & Palacios 6668 (holotype COL, 3 sheets; isotypes MO- 1456278, U 1607067, U 1607068, U 1607069, U 1610613).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
A7EA1648C6B85EB68D92DD79EA7064BF.taxon	description	Description. Herb 0.5 - 3 m tall. Leaves sheaths 15 - 30 mm diam; ligule obliquely truncate, 10 - 30 mm long, distally black to dark purple, with a minute, salient rim; petiole 5 - 20 mm long; sheaths, ligule and petiole glabrous, sparsely puberulous, or densely villose; lamina narrowly elliptic, 25 - 50 x 7 - 16 cm, adaxially sparsely to rather densely villose to puberulous, abaxially rather densely villose, base acute, apex acuminate (acumen 5 - 15 mm long). Inflorescence ovoid to subglobose, 6 - 23 x 6 - 12 cm, terminating a leafless shoot 20 - 90 cm long, rarely terminating a leafy shoot (Knapp & Vodicka 5524), sheaths withering and completely or partly falling off with age, obliquely truncate, 4 - 10 cm long, glabrous, sparsely puberulous to densely villose; bracts, bracteole, calyx, ovary, and capsule glabrous to rather densely puberulous. Flowers abaxially oriented; bracts orange-red, red, or yellow, coriaceous, ovate-triangular, 4 - 7 x 2.5 - 4 cm, apex acute to obtuse, more or less curved outwards to patent in living plants, callus 8 - 25 mm long, margins wooly in living material; bracteole boat-shaped, 20 - 30 mm long; calyx red, 10 - 18 mm long, lobes deltate, 2 - 8 mm long; corolla orange to yellow, ca. 50 mm long, glabrous, lobes elliptic, ca. 30 mm long; labellum yellow, lateral lobes rolled inwards and forming a tube ca. 10 mm diam, elliptic when spread out, ca. 35 x 25 mm, 3 - lobulate, lobules red, 5 - 6 mm long; stamen yellow, 35 - 40 x 12 - 15 mm, slightly exceeding the labellum, apex orange-red, acute, anther 9 - 10 mm long. Capsule ellipsoid to obovoid, 8 - 15 mm long.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
A7EA1648C6B85EB68D92DD79EA7064BF.taxon	distribution	Distribution. Costa Rica, Panama, Colombia (Antioquia, Choco) (Fig. 21 F).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
A7EA1648C6B85EB68D92DD79EA7064BF.taxon	etymology	Etymology. Costus callosus sp. nov. has been named after the very conspicuous thickened callose zone on its bracts.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
613A10E7BCF6580EA4166906D9BB532A.taxon	diagnosis	Diagnosis. Costus cochabambae sp. nov. (Figs 8, 9) superficially resembles C. comosus but differs by greenish appendaged bracts, a subglabrous corolla, a glabrous lower leaf side (except for the hairy primary vein), and a much longer ligule up to 25 mm long (vs. 1 - 3 mm).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
613A10E7BCF6580EA4166906D9BB532A.taxon	materials_examined	Type. Bolivia, Cochabamba: Prov. Chapare, Villa Tunari, 40 km hacia el Beni, por Chipiriri, 400 m, 24 Nov 1981, Beck 7320 (holotype LPB, specimen lacking a barcode; isotypes L, 2 sheets: L 1480367 & L 1480368 and spirit collection: L 0303088).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
613A10E7BCF6580EA4166906D9BB532A.taxon	description	Description. Herb ca. 1.7 m tall. Leaves sheaths 5 - 8 mm diam; ligule 15 - 25 mm long, unequally lobed, lobes obtuse; petiole ca. 5 mm long; sheaths, ligule and petiole densely to rather densely puberulous to villose; lamina narrowly elliptic to narrowly obovate, 17 - 30 x 6 - 8 cm, adaxially glabrous, abaxially glabrous with primary vein densely villose, strongly raised and prolonged as a prominent rim into the sheaths, base obtuse, apex acuminate (acumen 5 - 10 mm long). Inflorescence ovoid, 5 - 8 x 3 - 5 cm, terminating a leafy shoot; bracts, bracteole, and calyx densely to rather densely puberulous, ovary and capsule densely puberulo-sericeous. Flowers abaxially oriented; bracts green, coriaceous, broadly ovate, 1.5 - 2 x 1.5 - 2 cm; appendages green, foliaceous, reflexed when dry, broadly to shallowly ovate-triangular, 0.5 - 1.2 x 1.2 - 2 cm, apex obtuse to acute; bracteole boat-shaped, 15 - 17 mm long; calyx 9 - 12 mm long, lobes shallowly ovate-triangular, 2 - 3 mm long; corolla yellow, 30 - 40 mm long, subglabrous, lobes elliptic, 20 - 25 mm long; labellum yellow, lateral lobes rolled inwards and forming a tube ca. 10 mm diam, oblong-elliptic when spread out, ca. 20 x 15 mm, dentate; stamen yellow, ca. 20 x 5 mm, not exceeding the labellum, apex dentate, anther 8 - 9 mm long. Capsule not seen.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
613A10E7BCF6580EA4166906D9BB532A.taxon	distribution	Distribution. Bolivia (Cochabamba) (Fig. 21 G).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
613A10E7BCF6580EA4166906D9BB532A.taxon	etymology	Etymology. This species is named after the Bolivian department of Cochabamba, where it was collected.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
76FE595FBCE65E8689C99D7A88B3B36F.taxon	diagnosis	Diagnosis. Costus convexus sp. nov. (Fig. 10) shares with C. glaucus Maas the presence of glaucous shoots and leaves especially in young plants, but differs from that species by a globose inflorescence enveloped by the upper leaves and by the presence of distinctly convex bracts.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
76FE595FBCE65E8689C99D7A88B3B36F.taxon	materials_examined	Type. Colombia, Putumayo: 15 km S of Villagarzon on road to Puerto Umbria, 360 m, 17 Jul 2018, Maas, Maas-van de Kamer, Valderrama, Specht, Erkens & Rodriguez 10707 (holotype. L, 2 sheets).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
76FE595FBCE65E8689C99D7A88B3B36F.taxon	description	Description. Herb 3 - 5 m tall, young shoots and young leaves glaucous. Leaves sheaths ca. 20 mm diam; ligule truncate to obliquely truncate, 20 - 45 mm long; petiole 20 - 22 mm long, blushed in pink; sheaths, ligule and petiole glabrous; lamina narrowly elliptic, 31 - 57 x 12 - 16 cm, adaxially pale green and glabrous, abaxially green or purple in very young plants, glabrous to sparsely puberulous, base acute to slightly cordate, apex acuminate (acumen ca. 15 mm long). Inflorescence globose to ovoid, 8 - 20 x 5 - 8 cm, wrapped tightly by the upper leaves, terminating a leafy shoot; bracts, bracteole, calyx, ovary, and capsule glabrous. Flowers adaxially oriented to erect; bracts distinctly convex, reddish on the outer margins, greenish at the centre, coriaceous, ovate, 55 - 65 x 40 - 45 mm, apex obtuse, callus green, indistinct; bracteole boat-shaped, 40 - 45 mm long; calyx red, 15 - 25 mm long, lobes shallowly triangular to deltate, 4 - 10 mm long; corolla deep pink, 80 - 85 mm long, glabrous, lobes 50 - 60 mm long; labellum yellow, distal edge horizontally spreading, broadly obovate, 60 - 70 x 60 - 70 mm, lateral lobes strongly striped with pink or red, middle lobe reflexed, with yellow honey mark, margin irregularly dentate to lobulate; stamen dark pink, 30 - 40 x 12 - 15 mm, not exceeding the labellum, apex obtuse, anther 12 - 15 mm long. Capsule ellipsoid, 12 - 30 mm long.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
76FE595FBCE65E8689C99D7A88B3B36F.taxon	distribution	Distribution. Colombia (Putumayo), Ecuador (Morona-Santiago, Zamora-Chinchipe) (Fig. 21 H).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
76FE595FBCE65E8689C99D7A88B3B36F.taxon	etymology	Etymology. Costus convexus sp. nov. is named for the form of the bracts, which are distinctly convex; thus, the epithet convexus, an adjective meaning " convex or curved outwards " in Latin.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
C638FD6C4ABB5997B82B51E018F851AE.taxon	diagnosis	Diagnosis. Costus douglasdalyi sp. nov. (Fig. 11) can be confused with C. erythrothyrsus Loes., but differs from that species by its very narrow, often almost linear leaves.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
C638FD6C4ABB5997B82B51E018F851AE.taxon	materials_examined	Type. Brazil Acre: Mun. Tarauaca, Basin of Rio Jurua, Rio Tarauaca, Seringal Sumare, 19 Nov 1995, Daly, Silveira, Costa, Oliveira, Lima, Figueiredo & Ehringhaus 8606 (holotype U 1225319, isotype NY).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
C638FD6C4ABB5997B82B51E018F851AE.taxon	description	Description. Herb 1 - 4 m tall. Leaves sheaths 5 - 20 mm diam; ligule truncate, 2 - 3 mm long; petiole 3 - 8 mm long; sheaths, ligule and petiole glabrous to sparsely puberulous; lamina narrowly elliptic to linear, 20 - 35 x 2 - 7 cm, abaxially sometimes purple, glabrous to sparsely puberulous, primary vein sparsely covered with a row of erect hairs, adaxially glabrous, base acute to rounded, apex long-acute. Inflorescence ovoid to cylindric, 8 - 9 x 4 cm, enlarging to 13 - 17 x 5 - 7 cm in fruit, terminating a leafless shoot 45 - 70 cm long or rarely terminating a leafy shoot, sheaths obliquely truncate, 3 - 5 cm long, glabrous; bracts, bracteole, calyx, ovary, and capsule glabrous, apex of ovary and fruit sometimes sparsely puberulous. Flowers abaxially oriented; bracts red to dark red, coriaceous, broadly ovate, 2.5 - 4 x 2 - 3 cm, apex obtuse, callus 5 - 7 mm long; bracteole boat-shaped, 20 - 25 mm long; calyx red, 9 - 13 mm long, lobes shallowly triangular, 1 - 2 mm long; corolla red, pink, or pinkish orange, 45 - 55 mm long, glabrous, lobes narrowly ovate-elliptic to ovate-elliptic, 35 - 45 mm long; labellum pink to red, lateral lobes rolled inwards and forming a curved tube ca. 8 mm diam, broadly obovate to elliptic when spread out, 18 - 40 x 12 - 30 mm, irregularly 3 - 7 - lobulate, lateral lobes striped with red, middle lobe yellow, 3 - 5 mm long, irregularly crenulate; stamen pale pink, 15 - 40 x 7 - 10 mm, not exceeding the labellum, apex acute, anther 8 - 10 mm long. Capsule ellipsoid, 10 - 15 mm long.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
C638FD6C4ABB5997B82B51E018F851AE.taxon	distribution	Distribution. Peru (Ucayali), Brazil (Acre, Rondonia) (Fig. 21 I).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
C638FD6C4ABB5997B82B51E018F851AE.taxon	etymology	Etymology. This species is named for our dear colleague and friend Douglas Daly, whom PM and HM met many times in his home institute at the New York Botanical Garden Herbarium (NY) and who enabled us to undertake field work in the Brazilian regions of Acre and Amazonas. He also inspired CDS during her graduate studies at the New York Botanical Garden, providing insights into excellence in field research and tropical botany.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
28BF304A5167552F950A717D88578DAF.taxon	diagnosis	Diagnosis. Costus gibbosus sp. nov. (Fig. 12) can readily be recognized by the swollen margin of the lower leaf sheaths; the inflorescence is similar to that of Costus guanaiensis Rusby var. Costus guanaiensis macrostrobilus (K. Schum.) Maas, from which it differs by the horizontal orientation of the bract appendages with often incurved apex and the mostly glabrous leaves, bracts, and calyx.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
28BF304A5167552F950A717D88578DAF.taxon	materials_examined	Type. Ecuador, Pichincha: along the road from Aloag to Santo Domingo, 1150 m (" 3500 ft "), 17 Nov 1974, Plowman & Davis 4455 (holotype U 1212018; isotypes GH, USM).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
28BF304A5167552F950A717D88578DAF.taxon	description	Description. Herb 1.5 - 5 m tall. Leaves sheaths 15 - 35 mm diam, the margin of the lower ones swollen; ligule truncate to slightly 2 - lobed, often with a ridge near the apex, 7 - 14 mm long; petiole 10 - 15 mm long; sheaths, ligule and petiole glabrous to densely puberulous; lamina narrowly elliptic, 30 - 50 x 10 - 20 cm, slightly shiny above, pale green to slightly glaucous below, adaxially glabrous, rarely puberulous, abaxially glabrous, sometimes densely puberulous to villose, base acute to cordate, apex acuminate (acumen 15 - 20 mm long) to acute. Inflorescence ovoid to cylindric, 11 - 18 x 5 - 9 cm, terminating a leafy shoot; bracts, bracteole, and calyx glabrous, rarely rather densely puberulous, ovary and capsule glabrous to densely puberulo-sericeous. Flowers abaxially oriented; bracts red, coriaceous, broadly ovate, 40 - 50 x 30 - 40 mm; appendages green, foliaceous, erect, broadly triangular to triangular, 15 - 60 x 10 - 30 mm, often incurved at the apex; bracteole boat-shaped, 22 - 32 mm long; calyx red to pink, rarely white, (7 -) 12 - 20 mm long, lobes deltate to shallowly triangular, 2 - 5 mm long; corolla pale yellow, white, or pink, 60 - 70 mm long, glabrous, lobes ellliptic, 45 - 60 mm long; labellum pale yellow, orange, pinkish, or white, distal edge horizontally spreading, broadly obovate, 60 - 85 x 50 - 70 mm, lateral lobes erect, more or less striped with pink or red, middle lobe reflexed, with yellow honey mark, margin irregularly dentate to lobulate; stamen pink, red, yellow, or white, 40 - 50 x 12 - 15 mm, not exceeding the labellum, apex irregularly dentate, anther 9 - 13 mm long. Capsule ellipsoid to narrowly ellipsoid, 12 - 20 mm long.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
28BF304A5167552F950A717D88578DAF.taxon	distribution	Distribution. Ecuador (El Oro, Esmeraldas, Guayas, Loja, Manabi, Pichincha) (Fig. 22 A).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
28BF304A5167552F950A717D88578DAF.taxon	etymology	Etymology. Costus gibbosus sp. nov. is named for the swollen upper margin of the lower leaf sheaths.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
39BB13CA64F054F7B933299D0FB382DB.taxon	diagnosis	Diagnosis. Costus mollissimus sp. nov. (Fig. 13) shares with C. dirzoi Garcia-Mend. & G. Ibarra a distinct velutinous indument on most parts of the plant, but differs by having appendaged bracts and a very short ligule. Moreover, C. dirzoi has bracts with a distinct callus, absent in C. mollissimus.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
39BB13CA64F054F7B933299D0FB382DB.taxon	materials_examined	Type. Mexico, Chiapas: Mun. Chilon, 22 km from Temo in the direction of Palenque, 2 km from Patathel, near El Chich, 850 m, 4 Nov 1998, Ishiki Ishihara, Maas & Maas-van de Kamer 2400 (holotype L, 2 sheets: L 4368349 & L 436835; isotype ECOSUR).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
39BB13CA64F054F7B933299D0FB382DB.taxon	description	Description. Herb 0.5 - 2.5 m tall. Leaves sheaths 12 - 15 mm diam; ligule truncate, 1 - 4 mm long; petiole 10 - 15 mm long; sheaths, ligule and petiole densely velutinous; lamina narrowly elliptic, sometimes elliptic, 18 - 36 x 6 - 13 cm, slightly 5 - 8 - plicate, adaxially shiny, glabrous, abaxially densely velutinous, base acute, obtuse, to cordate, apex acuminate (acumen 5 - 15 mm long). Inflorescence cylindric to subglobose, 5 - 13.5 x 4 - 5 cm, terminating a leafy shoot; bracts, appendages of bracts, bracteole, calyx, ovary, and capsule densely velutinous. Flowers abaxially oriented; bracts green, red, or pink, coriaceous, broadly elliptic, 2 - 2.5 x 2 - 3 cm; appendages green, foliaceous, patent to slightly reflexed, triangular to broadly triangular, 0.5 - 3.5 x 1.2 - 2.5 cm, apex acute to obtuse; bracteole boat-shaped, 16 - 20 mm long; calyx red to pink, 9 - 10 mm long, lobes broadly to shallowly triangular, 2 - 5 mm long, with a hairy tuft at the apex; corolla cream, yellow, or pale orange, 50 - 60 mm long, densely velutinous, lobes narrowly elliptic, 30 - 40 mm long; labellum yellow, distal edge horizontally spreading, broadly obovate, 30 - 40 x 40 - 50 mm, lateral lobes dark red with yellow venation, middle lobe reflexed with yellow honey mark, margin dentate; stamen yellow, 30 - 35 x 10 - 12 mm, not exceeding the labellum, apex red, slightly 3 - dentate, anther ca. 8 mm long. Capsule broadly obovoid to obovoid, 12 - 17 mm long.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
39BB13CA64F054F7B933299D0FB382DB.taxon	distribution	Distribution. Mexico (Chiapas, Oaxaca, Tabasco, Veracruz) (Fig. 22 B).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
39BB13CA64F054F7B933299D0FB382DB.taxon	etymology	Etymology. This species is named after its very soft indument on the abaxial surface of the lamina, the word " mollis " meaning soft in Latin.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
21E5187F33005474943314D0CC978B38.taxon	diagnosis	Diagnosis. Costus obscurus sp. nov. (Fig. 14) can be recognized by its large, dark green leaves with dark purple undersides and densely whitish villose sheaths. It could superficially be confused with C. erythrophyllus Loes. and C. acreanus (Loes.) Maas, but these species never have densely villose sheaths.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
21E5187F33005474943314D0CC978B38.taxon	materials_examined	Type. Peru, Madre de Dios: Prov. Manu, near Shintuya, on road to Salvacion, 600 m, 9 Feb 1974, Plowman & Davis 5054 (holotype USM; isotypes GH, L 1483069, L 1480371, L 1480372).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
21E5187F33005474943314D0CC978B38.taxon	description	Description. Herb 1 - 1.5 m tall. Leaves sheaths 10 - 20 mm diam; ligule truncate, 10 - 15 mm long; petiole 8 - 12 mm long; sheaths, ligule and petiole densely to rather densely whitish villose; lamina narrowly elliptic, 32 - 45 x 9 - 17 cm, adaxially dark green, rather densely to densely whitish villose, abaxially dark purple, densely to sparsely whitish puberulous, base acute to cordate, apex acuminate (acumen 5 - 10 mm long). Inflorescence ovoid, 8 - 13 x 5 - 7 cm, terminating a leafy shoot; bracts, appendages of bracts, bracteole, calyx, ovary, and capsule rather densely to sparsely puberulous. Flowers abaxially oriented; bracts green in the exposed part, red or green in the covered part, coriaceous, broadly ovate-triangular, 35 - 45 x 30 - 35 mm; appendages green, erect, broadly ovate-triangular, 15 - 20 x 18 - 20 mm, or almost absent, apex rounded; bracteole boat-shaped, 35 - 37 mm long; calyx red, 25 - 27 mm long, deeply split on one side, lobes deltate to broadly triangular, ca. 2 mm long; corolla cream to yellow, ca. 75 mm long, glabrous, lobes narrowly elliptic, 55 - 60 mm long; labellum pale yellow, distal edge horizontally spreading, broadly obovate, ca. 60 - 70 x 60 - 70 mm, lateral lobes strongly striped with pink or red, middle lobe reflexed, with yellow honey mark, margin irregularly dentate to lobulate; stamen white to pink, 35 - 45 x 12 - 15 mm, not exceeding the labellum, apex pinkish red, deeply and irregularly lobed, anther 7 - 8 mm long. Capsule ellipsoid, 12 - 15 mm long.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
21E5187F33005474943314D0CC978B38.taxon	distribution	Distribution. Peru (Cuzco, Huanuco, Madre de Dios, San Martin) (Fig. 22 C).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
21E5187F33005474943314D0CC978B38.taxon	etymology	Etymology. Costus obscurus sp. nov. is known for its leaves having a very dark green adaxial surface and dark purple abaxial surface, and for growing in dark and shady places, hence the specific epithet obscurus (' obscurus' means ' dark, shady, " indistinct' in Latin). This species might also be considered " obscure " (in English: unclear, uncertain, unknown, or in doubt) because it has been confused by the authors in the past as either C. erythrophyllus Loes. or as C. acreanus (Loes.) Maas. Only recently has it been determined to be an undescribed species.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
69D7C492E44155FE9E3CCCCA0798E02C.taxon	diagnosis	Diagnosis. Costus oreophilus sp. nov. (Fig. 15) can be confused with C. laevis Ruiz & Pav., with which it shares the mostly green bracts and adaxially oriented flowers, but it is distinguished by the puberulous sheaths and leaves and a smaller ligule (3 - 10 mm vs. 5 - 20 mm long); moreover the corolla lobes are often recurved, a feature rarely seen in Costus.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
69D7C492E44155FE9E3CCCCA0798E02C.taxon	materials_examined	Type. Ecuador, Tunguruhua: Rio Verde Grande, 1500 m, 30 Mar 1956, Asplund 20068 (holotype S, 2 sheets S 06 - 1367 & S 06 - 13643; isotype GB).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
69D7C492E44155FE9E3CCCCA0798E02C.taxon	description	Description. Herb 3 - 4 m tall. Leaves sheaths 15 - 20 mm diam; ligule truncate, 3 - 10 mm long; petiole 5 - 10 mm long; sheaths, ligule and petiole densely to sparsely puberulous; lamina narrowly elliptic, 20 - 38 x 7 - 11 cm, adaxially shiny, glabrous, sometimes rather densely puberulous, abaxially green, densely to sparely puberulous to velutinous, base cordate to acute, apex acuminate (acumen 5 - 10 mm long). Inflorescence cylindric to ovoid, 7 - 12 x 3 - 6 cm, wrapped tightly by the upper leaves, terminating a leafy shoot; bracts, bracteole, calyx, ovary, and capsule sparsely puberulous to glabrous. Flowers adaxially oriented to erect; bracts green in the exposed part, red in the covered part, sometimes completely red, coriaceous, broadly ovate, 3.5 - 4.5 x 3 - 4 cm, apex obtuse, callus inconspicuous; bracteole boat-shaped, 18 - 31 mm long; calyx red, 6 - 12 mm long, lobes shallowly triangular, 3 - 4 mm long; corolla white to yellow, 50 - 60 mm long, glabrous, lobes recurved, narrowly obovate, 40 - 55 mm long; labellum white, distal edge horizontally spreading, broadly obovate, 70 - 75 x 70 - 75 mm, lateral lobes striped with red, middle lobe reflexed, with yellow honey mark, margin irregularly crenulate; stamen red to pink, 35 - 40 x 12 - 13 mm, not exceeding the labellum, apex red, irregularly dentate, anther 10 - 12 mm long. Capsule ellipsoid, c. 15 mm long.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
69D7C492E44155FE9E3CCCCA0798E02C.taxon	distribution	Distribution. Ecuador (Pastaza, Tungurahua, Zamora-Chinchipe) (Fig. 22 D).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
69D7C492E44155FE9E3CCCCA0798E02C.taxon	etymology	Etymology. The species name " Costus oreophilus " is derived from the Greek words oros (= mountain) and philos (= beloved) as this is a mountain-loving species.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
C79736589BB95B08846BF3556F31AB88.taxon	diagnosis	Diagnosis. Costus pitalito sp. nov. (Fig. 16) looks superficially like C. leucanthus Maas based on the shared light-coloured flowers and a very long ligule, but it differs from C. leucanthus by markedly obtuse ligule lobes and bracts with densely brownish villose margins.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
C79736589BB95B08846BF3556F31AB88.taxon	materials_examined	Type. Colombia, Cauca: forested roadside from San Juan de Villalobos to Pitalito, 1590 m, 19 Jul 2018, Maas, Maas-van de Kamer, Valderrama, Specht, Erkens & Rodriguez 10733 (holotype L, 2 sheets).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
C79736589BB95B08846BF3556F31AB88.taxon	description	Description. Herb 1.7 - 2.5 m tall. Leaves sheaths ca. 35 mm diam; ligule deeply 2 - lobed, 45 - 70 mm long, lobes rounded, obtuse; petiole 10 - 20 mm long; sheaths, ligule and petiole densely, brownish villose; lamina narrowly elliptic, 30 - 45 x 12.5 - 14 cm, adaxially glabrous but sparsely brownish villose when young, abaxially densely brownish villose, base acute, apex acuminate (acumen ca. 10 mm long). Inflorescence suglobose, 11 - 12 x 9 - 11 cm, terminating a leafy shoot; bracts rather densely villose, appendages of bracts sparsely villose to glabrous, its margins densely brownish villose, bracteole and calyx sparsely puberulous, ovary and capsule rather densely sericeous. Flowers abaxially oriented to erect; bracts red, coriaceous, broadly ovate, 3 - 4 x 2 - 3 cm; appendages green, foliaceous, cup-shaped, erect to patent, broadly ovate-triangular, 1 - 1.5 x 1 - 1.5 cm, apex obtuse to acute; bracteole 1 - to 2 - keeled, 30 - 32 mm long; calyx red, apex green, 20 - 22 mm long, lobes ovate-triangular, 10 - 12 mm long; corolla pale yellow to hyaline, base pinkish, 55 - 60 mm long, glabrous, lobes narrowly elliptic, 35 - 40 mm long, with filiform apex; labellum light yellow to cream, darker yellow in throat, distal edge horizontally spreading, broadly obovate, ca. 70 x 70 - 80 mm, margin irregularly dentate to crenate; stamen cream, ca. 50 x 15 mm, apex reflexed, irregularly dentate, not exceeding the labellum, anther ca. 13 mm long. Capsule ellipsoid, ca. 25 mm long.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
C79736589BB95B08846BF3556F31AB88.taxon	distribution	Distribution. Colombia (Cauca, Putumayo) (Fig. 22 E).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
C79736589BB95B08846BF3556F31AB88.taxon	etymology	Etymology. This species is named " pitalito " after its type locality near Pitalito, in the Colombian department of Cauca.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
28B17AA13A495833A72419FB53764B67.taxon	diagnosis	Diagnosis. Costus prancei sp. nov. (Fig. 17) looks quite similar to C. sprucei Maas (a species restricted to the Brazilian state of Para) and has been confused with it in the past, both sharing most of the vegetative and floral characters, but this species has yellow to orange flowers whereas they are pinkish red in C. sprucei.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
28B17AA13A495833A72419FB53764B67.taxon	materials_examined	Type. Brazil, Acre: vicinity of Serra da Moa, 22 Apr 1971, Prance, Maas, Kubitzki, Steward, Ramos, Pinheiro & Lima 12265 (holotype U, 2 sheets: U 1607120 & U 1603130 (spirit collection); isotypes INPA, NY 00867011).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
28B17AA13A495833A72419FB53764B67.taxon	description	Description. Herb 1 - 1.5 m tall. Leaves sheaths 8 - 10 mm diam; ligule truncate, 2 - 7 mm long; petiole 2 - 8 mm long; sheaths, ligule, and petiole densely to sparsely villose; lamina narrowly elliptic, 11 - 25 x 4 - 7 cm, adaxially densely villose to glabrous with a dense row of hairs along the primary vein, abaxially densely puberulous to villose, base acute, rounded, or cordate, apex acuminate (acumen ca. 15 mm long). Inflorescence cylindrical, 3 - 15 x 1.5 - 4 cm, terminating a leafy shoot; bracts, bracteole, calyx, ovary, and fruit densely puberulo-villose to glabrous. Flowers abaxially oriented; bracts red, coriaceous to chartaceous, broadly to depressed ovate, 1.5 - 2.5 x 1.5 - 3 cm, callus 3 - 5 mm long; bracteole boat-shaped, 9 - 15 mm long; calyx red to pale orange-red, 6 - 12 mm long, lobes shallowly triangular, 1 - mm long; corolla yellow to orange (2 labels indicated cream and pink to orange!), 20 - 30 mm long, glabrous, lobes narrowly elliptic, 20 - 25 mm long; labellum yellow to orange, lateral lobes involute and forming a straight tube 7 - 8 mm diam, oblong-obovate when spread out, 20 - 25 x 12 - 16 mm, irregularly lobulated, lobules 0.5 - 5 mm long; stamen yellow, 23 - 25 x 7 - 8 mm, slightly exceeding the labellum, apex rounded, anther ca. 6 mm long. Capsule ellipsoid to subglobose, 6 - 7 x 5 - 7 mm.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
28B17AA13A495833A72419FB53764B67.taxon	distribution	Distribution. Brazil (Acre, Amazonas, Rondonia), Peru (Loreto, San Martin) (Fig. 22 F).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
28B17AA13A495833A72419FB53764B67.taxon	etymology	Etymology. This species is named after our friend and dearest colleague Sir Ghillean Prance, who invited us (PM and HM) in 1971 to join various of his expeditions into the Brazilian Amazon region and who inspired me (PM) very much to continue working as a Neotropical taxonomist.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
73F68C6A0B2251BAB9EF7C273F37D7EA.taxon	diagnosis	Diagnosis. Costus pseudospiralis sp. nov. (Fig. 18) looks superficially quite similar to C. spiralis (Jacq.) Roscoe, but differs by the orientation of the flowers (floral opening facing abaxially v adaxially) and a cordate leaf base. It differs from C. douglasdalyi by the inflorescence terminating a leafy shoot instead of terminating a shorter leafless shoot (sometimes referred to as ' basal' in the literature), the presence of villose indumentum on most of its vegetative parts (vs. glabrous or sparsely puberulous), and a cordate (vs. acute to rounded) leaf base.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
73F68C6A0B2251BAB9EF7C273F37D7EA.taxon	materials_examined	Type. Bolivia, Beni: km 4 of road from Riberalta to Santa Maria, 150 m, 22 Jan 1999, Maas, Maas-van de Kamer & Apaza 8751 (holotype U, 2 sheets: U 1610003 & U 1610004; isotypes K, MO, USZ).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
73F68C6A0B2251BAB9EF7C273F37D7EA.taxon	description	Description. Herb 1.5 - 2 m tall. Leaves sheaths 10 - 15 mm diam; ligule obliquely truncate, 5 - 8 mm long; petiole 3 - 5 mm long; sheaths, ligule and petiole densely villose; lamina narrowly elliptic, 20 - 43 x 4 - 12 cm, adaxially densely to rather densely villose, abaxially densely villose, base cordate, apex acuminate (acumen 10 - 15 mm long). Inflorescence ovoid, 4 - 12 x 3 - 6 cm, terminating a leafy shoot; bracts, bracteole, calyx, ovary, and capsule glabrous. Flowers abaxially oriented; bracts red to dark red, coriaceous, broadly ovate, 2.5 - 3.5 x 2.5 - 3.5 cm, apex obtuse, callus 5 - 7 mm long, sometimes with a small, deltate appendage c. 5 x 5 mm; bracteole boat-shaped, 15 - 20 mm long; calyx red, 8 - 11 mm long, lobes shallowly ovate-triangular to very shallowly ovate-triangular deltate, 1 - 2 mm long; corolla dark salmon pink, 45 - 50 mm long, glabrous, lobes narrowly obovate-elliptic, 30 - 35 mm long; labellum pale salmon pink, apex and centre white, distal part of middle lobe yellowish, lateral lobes rolled inwards and forming a slightly curved tube 6 - 12 mm diam, oblong-obovate when spread out, 30 - 35 x 20 - 25 mm, apex irregularly 5 - lobulate; stamen salmon pink, ca. 30 x 7 mm, not exceeding the labellum, apex white, rounded, anther 8 - 10 mm long. Capsule ellipsoid, 10 - 20 mm long.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
73F68C6A0B2251BAB9EF7C273F37D7EA.taxon	distribution	Distribution. Bolivia (Beni), Brazil (Rondonia) (Fig. 22 G).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
73F68C6A0B2251BAB9EF7C273F37D7EA.taxon	etymology	Etymology. This species is named " pseudospiralis ", referring to its resemblance to C. spiralis.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
191887D029815EFAA87A8804961FE2FE.taxon	diagnosis	Diagnosis. Costus rubineus sp. nov. (Fig. 19) looks somewhat similar to C. scaber Ruiz & Pav. but differs from that species by a larger calyx (9 - 15 vs. 3 - 7 mm), larger bracteole (20 - 28 vs. 9 - 12 mm), larger corolla (50 - 60 vs. 35 - 40 mm), and a labellum which is distinctly lobulate at the apex vs. entire in C. scaber; furthermore it is restricted to high elevations whereas C. scaber is mostly a lowland species; C. rubineus also lacks the row of hairs along the adaxial midvein of the lamina, which is so typical for C. scaber.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
191887D029815EFAA87A8804961FE2FE.taxon	materials_examined	Type. Peru, Pasco: Prov. Oxapampa, Gramazu, 1961 m, 17 Mar 2005, Rojas G., Vasquez Chavez & Francis 3574 (holotype L 4196133; isotypes HUT, MO- 2152325, USM).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
191887D029815EFAA87A8804961FE2FE.taxon	description	Description. Herb 0.5 - 4 m tall. Leaves sheaths 15 - 30 mm diam; ligule truncate to slightly lobed, 2 - 7 mm long; petiole 3 - 8 mm long; sheaths, ligule and petiole densely sericeous to glabrous; lamina narrowly elliptic, 20 - 37 x 5 - 13 cm, adaxially glabrous, abaxially rather densely villose to almost glabrous, base obtuse to slightly cordate, apex acuminate (acumen 10 - 15 mm long) to acute. Inflorescence ovoid, 7 - 11 x 4 - 6 cm, terminating a leafy shoot; bracts, bracteole, and calyx rather densely puberulous to glabrous, ovary and capsule densely sericeous. Flowers abaxially oriented; bracts dark ruby red to red, coriaceous, broadly ovate, 3 - 4 x 2.5 - 4 cm, apex obtuse, callus 6 - 10 mm long; bracteole boat-shaped, 20 - 28 mm long; calyx red to pink, 9 - 15 mm long, lobes very shallowly triangular, 2 - 3 mm long; corolla pink to orange, 50 - 60 mm long, glabrous, lobes narrowly elliptic, 40 - 50 mm long; labellum yellow, distal part red, lateral lobes rolled inwards and forming a curved tube ca. 10 mm diam, oblong-obovate when spread out, 30 - 50 x 18 - 20 mm, 5 - lobulate, lobules narrowly ovate-triangular, ca. 4 mm long; stamen yellow, 30 - 45 x 7 - 10 mm, not or slightly exceeding the labellum, apex red, irregularly dentate, anther 8 - 9 mm long Capsule obovoid, ca. 13 mm long.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
191887D029815EFAA87A8804961FE2FE.taxon	distribution	Distribution. Peru (Huanuco, Pasco) (Fig. 22 H).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
191887D029815EFAA87A8804961FE2FE.taxon	etymology	Etymology. Costus rubineus sp. nov. is named in reference to the Spanish explorer Hipolito Ruiz who visited in August 1780 the place called Chinchao in the Peruvian department of Huanuco. In his journal, he mentioned the collection of a plant he referred to as " Costus ruber ", but his collection was lost in a shipwreck off the coast of Portugal, and this species' name was never again mentioned in the journal. Since there is already a C. ruber C. Wright ex Griseb. (a synonym of C. pulverulentus C. Presl), we cannot use that name but are using the very apt name of C. rubineus to reflect the beautiful ruby-red colour of the bracts. The first author of this species visited the Chinchao region in 2016 and found at that locality specimen which he believed to be the same species as Ruiz mentioned in his journal (Skinner 2016).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
A8C88702988454E3B7F278BEECF5CEC4.taxon	diagnosis	Diagnosis. Costus whiskeycola sp. nov. (Fig. 20) looks quite similar to Costus erythrophyllus Loes., sharing many features of inflorescence and flowers, but it is markedly different in their leaves which lack the distinct plication and which have a dark, olive green adaxial surface.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
A8C88702988454E3B7F278BEECF5CEC4.taxon	materials_examined	Type. Colombia, Putumayo: Km 42 of Mocoa-Puerto Asis Road, Quebrada El Whiskey, Finca Santa Marta, Hilltop forest, c. 400 m (" 1260 ft "), 5 Nov 1974, Plowman & Davis 4396 (holotype COL; isotype PSO).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
A8C88702988454E3B7F278BEECF5CEC4.taxon	description	Description. Herb 0.5 - 0.7 m tall. Leaves sheaths 10 - 18 mm diam; ligule 10 - 20 mm long, obliquely truncate; petiole 5 - 15 mm long; sheaths, ligule and petiole glabrous, purple-red to green; lamina ovate-elliptic to narrowly ovate-elliptic, 22 - 29 x 10 - 13 cm, dark, olive green adaxially, red-purple to dark purple abaxially, with 5 - 6 dark green bands corresponding with slightly raised veins above, adaxial and abaxial surfaces both glabrous, base acute, apex acute to shortly acuminate (acumen 3 - 5 mm long). Inflorescence ovoid, ca. 7 x 4.5 cm, terminating a leafy shoot; bracts and appendages of bracts, bracteole, calyx, and ovary glabrous. Flowers abaxially oriented; bracts red, coriaceous, broadly ovate, 3 - 4 x 2 - 3.5 cm; appendages green, foliaceous, ascending, triangular-ovate, 2.5 - 5 x 2 - 3.5 cm, apex acute; bracteole boat-shaped, 24 - 30 mm long; calyx red, 12 - 20 mm long, lobes very shallowly triangular, 2 - 5 mm long; corolla white, 60 - 75 mm long, glabrous, lobes narrowly elliptic, 45 - 60 mm long; labellum white, distal edge horizontally spreading, broadly obovate, 60 - 70 x 50 mm, lateral lobes striped with red, middle lobe reflexed with yellow honey mark, irregularly lobulate, margin crenulate; stamen white, tinged with red, 35 - 40 x 13 - 14 mm, not exceeding the labellum, apex 3 - dentate, anther 8 - 10 mm long. Capsule not seen.	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
A8C88702988454E3B7F278BEECF5CEC4.taxon	distribution	Distribution. Colombia (Putumayo). Ecuador (Napo), Peru (Loreto) (Fig. 22 I).	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
A8C88702988454E3B7F278BEECF5CEC4.taxon	etymology	Etymology. This species has been named after its type locality El Whiskey (Putumayo, Colombia), with " cola " the Latin for " living in ".	en	Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio, Specht, Chelsea D. (2023): Eighteen new species of Neotropical Costaceae (Zingiberales). PhytoKeys 222: 75-127, DOI: http://dx.doi.org/10.3897/phytokeys.222.87779, URL: http://dx.doi.org/10.3897/phytokeys.222.87779
