BUTACEJS. 



427 



found in the Mediterranean region, the East, tropical Asia, and as 

 far as Mexico. 1 



The flowers of Tribulus (Fr., Herses 1 ) (figs. 511-513) are also 

 hermaphrodite, regular, pentamerous, with imbricated or contorted 

 sepals. Of the six stamens, 3 inserted round the base of the hypo- 

 gynous disk with ten lobes, five are longer, alternipetalous, and 



Tribulus terrestris. 



Fig. 511. 

 Flower (f ). 



Fig. 512. 

 Long. sect, of flower (^). 



Trilulus ferrestris. 



more exterior, with a filament provided outwardly with a basilar 



gland. All have a two-celled, introrse anther, dehiscing by two 



longitudinal clefts. 4 The superior gynaeceum is formed 



of a sessile ovary, which in T. terrestris, and other 



analogous species, has five oppositipetalous cells, and 



is surrounded by a short, thickset style, divided into 



five vertical stigmatiferous lobes, alternating with the 



cells. In each of them are several descending and 



anatropous ovules, inserted in the internal angle, 



with superior and exterior micropyle. 5 In certain 



other species of this genus, there is a greater number 



of ovary cells, containing either numerous descending ovules, or 



sometimes only one. 



Fig. 513. 



Fruit (|). 



1 Reiciib., Ic. Fl. Germ., v.* t. 158. — 

 Sibth., Fl. Gra-e., t. 455. — Boiss., Fl. Or., i. 

 917. — Walp., Rep., i. 517; ii. 824; Ann., iv. 

 414; vii. 509. 



2 Tribulus T., Inst., 265, t. 141.— L., Gen., 

 ii. 532. — Adans., Fam. des PI., ii. 507. — J., 

 Gen., 293.— G.ERTN., Fruct., i. 335, t. 69.— 

 Lajik., III., t. 316.— Poie., Diet., viii. 43; 

 Suppl., v. 338.— DC, Prodr., i. 703 (part.).— 

 A. Jtrss., in Mem. Mus„ xii. 451, t. 14, fig. 1. — 

 Turp., in Diet. Sc. Nat. Atl., t. 123.— Endl., 

 Gen., n. 6030. — Payer, Organog., 60, t. 14.— 

 A. Gray, Gen. III., t. 145.— B. H., Gen., 264, 



n. 1. — H. Bn., in Adansonia, x. 313 (inch: 



Ehrenbergia Mart., Heterozygia Bge., Kail- 

 slruemia Scop., Tribulopsis K. Br). 



3 Five are often sterile, or wanting in Tri- 

 bulopsis (R. Be., in Slurt Exp. App., 70). 



♦The pollen is, according to H. Mohi, (in 

 Ann. Sc. Nat., ser. 2, iii. 339), ,; spherical, 

 membrane externally cellular (T. alatus, T. 

 terrestris, T. larmginosus, Ehrenbergia tribu- 

 loides)." 



5 With double coat. Generally (lisp >sed in 

 one single vertical series at maturity. 



