COMPOSITA. 4161 
6. Ambrosia psilostachya, DC. Prodr. v. p. 526. 
Texas.—Norta Mzxico, between San Fernando and Matamoros (Berlandier, 2280), 
Sonora (Wright). Hb. Kew. 
87. FRANSERIA. 
Franseria, Cav. Ic. ii. p. 78, t. 200; Benth. et Hook. Gen. Plant. ii. p. 354. 
About ten herbaceous and half-shrubby species, restricted to North America and 
Peru and Chili. 
1. Franseria ambrosioides, Cav. Ic. ii. p. 79, t. 200; A. Gr. in Bot. Calif. i. 
p. 346. 
Nortu Mexico, Sierra Madre (Seemann, 2036); not rare in Mexico (ex A. Gray, loc. 
cit.). Hb. Kew. 
2. Franseria deltoidea, Torr. Pl. Fremont. p. 15, et Bot. U.S. & Mex. Bound. 
Surv. p. 87. 
CaLirornia.—NortH Mexico, common on the Gila (ex Torrey). 
3. Franseria dumosa, A. Gr. in Rep. Frem. 2nd. Exped. p. 316, et in Bot. 
Calif. i. p. 340. 
Franseria albicaulis, Torr. Pl. Fremont. p. 16. 
Ca.Lirornia.—NortH Mexico, Sonora. 
4. Franseria hookeriana, Nutt. in Trans. Amer. Phil. Soc. n. ser. vii. p. 345 ; 
Torr. & Gray, Fl. N. Am. ii. p. 293. 
Ambrosia acanthicarpa, Hook. F1. Bor.-Am. 1. p. 309. 
SASKATCHEWAN southward to—Norru Mexico, El Paso to Sonora, common; valley 
west of the Chiricahui Mountains. Hb. Kew. | 
5. Franseria tenuifolia, A. Gr. Pl. Fendl. p. 80, et in Bot. Calif. i. p. 346. 
Catirornia ; Texas.—Nortu Mexico, Sonora (ex A. Gray), region of San Luis Potosi, 
6000 to 8000 feet (Parry & Palmer, 433). Hb. Kew. 
88. XANTHIUM. 
Xanthium, Linn. Gen. Plant. n. 1056; Benth. et Hook. Gen. Plant. i. p. 355. 
Annual herbs, one or two of which are now widely diffused in warm and temperate 
regions, though believed to have originally spread from America. Wallroth has 
described twenty-one species, which Bentham and Hooker would reduce to four. 
1. Xanthium macrocarpum, DC. Prodr. v. p. 523. | 
Mexico, valley of Mexico (Bourgeau, 943), without locality (Graham).—Widely 
dispersed in TRopicaL AMERICA, and also in some parts of the OLD Worip. Hb. Kew. 
