Monographs Details: Costus spiralis var. villosus Maas
Authority: Maas, Paulus J. M. 1972. Costoideae (Zingiberaceae). Fl. Neotrop. Monogr. 8: 1-140. (Published by NYBG Press)
Description:Latin Diagnosis - Differt a varietate typica foliis et petiolo dense vel sparse villosis. Pollen size 106-128 /x. Exine 2-4 /z thick. Number of pores 6-9. Porus diam 20-30 µ (.Florschütz & Maas 2788 and 2790 from Suriname). Chromosome number 2n = 18 (Florschütz & Maas 2690 and 2790 from Suriname).

Distribution and Ecology - (Fig 48, 4). The Guianas and Pará, Brazil; at edges of savannas, in savanna forests and on granitic outcroppings in sun-exposed spots; one collection from edge of swamp on muddy soil; from sea-level to 350 m.

Discussion:Costus spiralis can easily be recognized in the field by its red inflorescence and pinkish-red to salmon-red flowers. It is very close to C. spicatus (see under that species) and C. erythrocoryne; it diverges from the latter in its red instead of yellow flowers and its somewhat shorter calyx. Like many other species of Costus, C. spiralis occurs in two forms: one with the inflorescence terminating a leafy stem, the other with a separate leafless flowering shoot. Some of the specimens of the latter resemble the typical C. spiralis very much, but five specimens deviate in a few characters: margins of the bracts dilacerating into fibers and calyx 12-15 mm long (instead of 7-10 mm as in the typical C. spiralis); in both characters they closely match C. erythrocoryne, but the flower-color and the leaf-shape fall more within the circumscription of C. spiralis. Only a few poorly preserved flowers being present on the sheets, the floral characters could not be adequately studied and therefore no final solution of this problem can be given. The specimens studied are: Prance & Pennington 2019 (NY, U) from km 60 of road BR 22, Capanema to Maranhão, Pará, Brazil; Cowan 38752 (NY, P) from Montagne de Kaw, French Guiana; Fanshawe, For. Dep. B. G. 3825 (K) from Bartica-Potaro Road, Guyana; Froes 34249, 34328 (IAN) both specimens from Rio Piria, Para, Brazil.

I am not quite sure of the identity of the following specimens: Bang 912, Kuntze sn and Rusby 1295 from Bolivia and named these specimens C. ? laevis, but they also resemble C. spiralis.
Distribution:Guyana South America| Suriname South America| French Guiana South America| Brazil South America| Pará Brazil South America|