PLANT FAMILY: Costaceae
BOTANICAL NAME: Costus guanaiensis var. guanaiensis
FORMAL SCIENTIFIC NAME: Costus guanaiensis Rusby
Paul Maas describes var. guanaiensis as follows: "Sheaths densely ferrugineous-hirsute [stiff erect brown hairs with swollen base] with the upper side of the leaves being strigose [stiff appressed hairs] to glabrous [lacking hairs], but the lower side of the leaves are ferrugineous-villose "[long, soft, erect brown hairs]. It can produce an inflorescence either terminally on a leafy stem or basal on a leafless stem. Since this is the only variety described as having brown hairs, I am assuming any brown-haired C. guanaiensis will be from var. guanaiensis.
According to Maas, the distribution of var. guanaiensis is southern (Amazonian) Colombia, eastern Peru and western Bolivia with some specimens in Costa Rica. The distribution of var. macrostrobilus is more prevalent in Central America extending to the Pacific side of Colombia (Depts of ChocÃ³, Antioquia and El Valle (a/k/a Valle de Cauca) and Ecuador (Esmeraldas-Los Rios), then also into northwestern South America -Venezuela and Guyana. There is much overlap between the two. The third variety tarmicus is found in Chiapas Mexico, then also in northwestern South America, but there were some scattered specimens also reported in western Colombia, Ecuador and Peru, so it is not clear at all based on geography.
A form I saw in Costa Rica, Parque Nacional Tapanti was very common along trail leading from the road down to the river. The plant was very tall, to 4 meters, with straight stems and extremely villous with brown hairs. Until I saw the flowers I took it to be Costus villosissimus, but I believe it is a form of Costus guanaiensis var. guanaiensis. Other forms from Amazonian Peru are believed to be this variety.
R2876 (PID7531) Costus 'Sweet Charlotte'. Has dense soft hairs on both sides of the leaves.
R3116 and R3123 (PID 7529) Costus 'Emerald Crinkles'. Collected near Iquitos, Peru. Has dense soft hairs on both sides of the leaves.
R3380 - basal flowering form collected in Huanuco, Peru