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.
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 × 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 × 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 × 2–3 cm; appendages green, foliaceous, cup-shaped, erect to patent, broadly ovate-triangular, 1–1.5 × 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 × 70–80 mm, margin irregularly dentate to crenate; stamen cream, ca. 50 × 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.