Eighteen new species of Neotropical Costaceae (Zingiberales) Author Maas, Paul J. M. Naturalis Biodiversity Centre, Botany, P. O. Box 9517, 2300 RA Leiden, Netherlands Author Maas-van de Kamer, Hiltje Naturalis Biodiversity Centre, Botany, P. O. Box 9517, 2300 RA Leiden, Netherlands Author Andre, Thiago https://orcid.org/0000-0003-4148-3662 Universidade de Brasilia, Departamento de Botanica, Campus Universitario Darcy Ribeiro, Asa Norte, Brasilia (DF), Brazil Author Skinner, David https://orcid.org/0000-0003-4585-925X Le Jardin Ombrage, Tallahassee, (Private botanical garden, Botanic Gardens Conservation International - BGCI - registration ID 50148), Florida, USA Author Valderrama, Eugenio Cornell University, Section of Plant Biology and the L. H. Bailey Hortorium, School of Integrative Plant Science, Ithaca, NY, USA Author Specht, Chelsea D. https://orcid.org/0000-0001-7746-512X Cornell University, Section of Plant Biology and the L. H. Bailey Hortorium, School of Integrative Plant Science, Ithaca, NY, USA cdspecht@cornell.edu text PhytoKeys 2023 2023-03-22 222 75 127 http://dx.doi.org/10.3897/phytokeys.222.87779 journal article http://dx.doi.org/10.3897/phytokeys.222.87779 1314-2003-222-75 348E6053A6D55787993694B23682FDE9 Costus pitalito C.D.Specht & H.Maas sp. nov. 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. Figure 16. Costus pitalito C.D.Specht & H.Maas A inflorescence as seen from above showing hairs on the margins of the bracts B close-up of single flower with attached bracteole (bl) indicating the calyx (ca), petals (pe) and labellum (lab) C indument of abaxial leaf surface D flower as viewed from the top showing the open labellum (lab) and single fertile stamen (st) E close-up of swollen leaf sheaths F leaf ligule. Photos of type specimen Maas et al. 10733 taken prior to pressing A-E by Chelsea Specht, F by Paul Maas. 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) . 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. Distribution. Colombia (Cauca, Putumayo) (Fig. 22E ). Habitat and ecology. Along forested roadsides, at an elevation of ca. 1600 m. Flowering and fruiting: May and July. Etymology. This species is named "pitalito" after its type locality near Pitalito, in the Colombian department of Cauca. Paratypes. Colombia. Putumayo : Mun. Villagarzon , carretera a Puerto Asis, 4 May 1994, Fernandez-Alonso et al. 11440 (COL). Notes. Costus pitalito looks superficially like C. leucanthus Maas by its white flowers and a very long ligule, but it differs by obtuse ligule lobes and bracts with densely brownish villose margins.