158 ZYGOPHYLLACER, 
- Order XXIX. ZYGOPHYLLACE. 
Zygophyllacee, Benth. et Hook. Gen. Plant. i. p. 262. 
Herbs or shrubs, very few arboreous, comprising about 100 species belonging to 
seventeen genera. They are dispersed throughout tropical and subtropical regions, 
though they are rare in subtropical regions of the southern hemisphere. 
1. TRIBULUS. 
Tribulus, Linn. Gen. Plant. n. 532; Benth. et Hook. Gen. Plant. i. p. 264. 
About fifteen herbaceous species, represented in nearly all warm countries of the 
world. One or two species are amphigeous. 
1. Tribulus cistoides, Linn. Sp. Pl. p. 554; A. Gray, Il Gen. t. 145. 
The Southern States of Norra America to—Soura Mexico, plain of Oaxaca, 5000 feet 
(Galeotti, 3062; Coulter, 782).—Widely spread in Tropical and Subtropical SourH 
AMERICA and the West Inprzs. Occurring also in Austratia, Asta, and Arrica, and 
some of the Paciric Isuanps. Hb. Kew. 
2. Tribulus grandiflorus, Benth. et Hook. Gen. Pl. i. p. 264. 
Kallstremia grandiflora, Torr. in A. Gray, Pl. Wright. i. p. 28. 
_ Texas; New Mexico; Arizona; CaLirornia.— Nort Mexico, Sonora Alta (Coulter, 
7 83); Sourn Mexico, between Tehuantepec and the Pacific Ocean (Andrieux, 474); 
GUATEMALA, roadsides &c. (Bernoulli, 756). Hb. Kew. 
3. Tribulus maximus, Linn. Sp. Pl. p. 553. 
Kallstremia maxima, Torr. et Gr. Fl. N. Am. i. p. 218; Gray, Gen. IIL. ii. p. 117, t. 146. 
NortH Mexico, Zacatecas (Hartweg), Monterey (Eaton & Edwards), Chihuahua 
(Potts); SourH Mexico, Zimapan (Coulter, 780 and 781); Guarumata (Friedrichsthal) ; 
NicaRacua, in plantations (Levy); Panama (S. Hayes, 728).—A very variable and 
exceedingly common plant in Tropical and Subtropical America, including some of the 
West-Inpian Isuanps. It has also been collected in Western Tropica, Arrica. Hb. 
Kew. - 
[Fagonia is a small widely dispersed genus of this family likely to exist in Mexico. 
It is represented in California and Chili.] 
2. LARREA. 
Larrea, Cav. Ann. Cienc. Nat. ii. p. 119; Benth. et Hook. Gen. Plant. i. p. 267. 
Four shrubby species restricted to America, ranging from Texas, California, and 
Mexico to the Andes of South America, and reappearing in South Brazil. 
