198 COMPOSITE. 
138. HIDALGOA. 
Hidalgoa, Liav. et Lex. Nov. Veg. Descr. i. p. 15; Benth. et Hook. Gen. Plant. ii. p. 386. 
A climbing herbaceous or shrubby monotype. 
Bentham and Hooker, loc. cit., state that there are two species: but this seems to be 
a slip; for we find no evidence of the existence of a second species. 
1. Hidalgoa ternata, Llav. et Lex. Nov. Veg. Descr. i. p.15; Less. in Linnea, 
vi. p. 213. | 
Hidalgoa lessingii, DC. Prodr. v. p. 511. 
Melampodium? ternatum, DC. Prodr. v. p. 521. 
Sourn Mexico, Cordova, forest of Chiquihite (Bourgeau, 2122), Misantla and Cuesta 
Grande de Jalacingo (Schiede & Deppe), near the last falls of the Rio Blanco, not far 
from San José del Corral (La Llave)—Ecuapor. Hb. Kew. 
139. THELESPERMA. 
Thelesperma, Less. in Linnea, p. 511; Benth. et Hook. Gen. Plant. ii. p. 387. 
An American genus of about four or five half-shrubby and herbaceous species, whereof 
one is a native of Extratropical South America, and the rest are natives of the Mexican 
region. | 
1. Thelesperma gracile, A. Gr. in Hook. Kew Journ. Bot. i. p. 252; in Torr. 
Bot. U.S. & Mex. Bound. Surv. p. 90. 
Bidens gracilis, Torr. in Ann. Lyc. N. York, it. p. 215. 
Cosmidium gracile, Torr. & Gr. Fl. N. Am. ii. p. 850. 
Arkansas; New Mexico.—Nortu Mexico, Sonora (Schott), without locality (Gregq). 
Hb. Kew. 
2. Thelesperma longipes, A. Gr. Pl. Wright. i. p. 109. 
Nortu Mexico, Rio San Pedro (Wright), Camp Bowie, 8S. Arizona (Rothrock). Hb. 
Kew. 
3. Thelesperma simplicifolium, A. Gr. in Hook. Kew Journ. Bot. i. p. 252. 
Cosmidium simplicifolium, A. Gr. Pl. Fendl. p. 86. 
NortH Mexico, San Pedro river, Sonora (Schott), Buena Vista, Coahuila (Gregg). 
Hb. Kew. 
140. COSMOS. 
Cosmos, Cav. Ic. Pl. i. p.9; Benth. et Hook. Gen. Plant. ii. p. 387. 
An exclusively American genus of herbs, dispersed from Mexico to Bolivia. It is 
difficult to estimate the number of species, as the forms are very numerous; but there 
must be at least a dozen. 
1. Cosmos bipinnatus, Cav. Ic. Pl. i. p. 2, t. 14; DC. Prodr. v. p. 606. 
Georgia bipinnata, Spreng. Syst. iii. p. 611. 
