Vol 49. No. 10 
BULLETIN 
OF THE 
TORREY BOTANICAL CLUB 
OCTOBER, 1922 
The genus Costus in Central America 
W. W. ROWLEE 
(WITH PLATES 12-15) 
As at present organized the genus Costus L. is composed of 
about one hundred species, divided almost equally between the 
Eastern and Western Hemispheres. Very few species occur in 
both hemispheres. The American species are most abundant 
in regions of heavy rainfall, maximum humidity and high 
temperature of both air and soil. The genus ranges from one 
Tropic to the other; it occurs wherever conditions are favorable 
in hot, warm and temperate regions, but is not found in high 
and cold districts. 
In any given locality the species do not usually appear abun- 
dant, but are scattered about in deep woodlands and undisturbed 
jungle. The plants are herbaceous perennials with spirally 
arranged leaves. The stems or culms are simple and represent 
branches arising ‘from a system of underground rootstocks. 
They thus form gregarious clusters, some of the culms 1emaining 
sterile and others producing spikes of flowers. In some cases the 
mats are more extensive than in others, this depending partly 
upon age and partly upon the habit of the plant. The leaves are 
ovate to lanceolate in outline and invariably entire. 
In Spanish American countries members of the genus are 
called ‘‘canagria’”’ or ‘‘cana agria,”” meaning “bitter cane,” 
[The BULLETIN for September (49: 259-282. pi. 10, 11) was issued Sep- 
tember 22, 1922.] 
283 
