160 XXX. ZYGOPHTLLACE^. 



coriaceous or cnistaceous, souietitnes dividing into 2-10 dehiscent or 

 indehiscent (sometimes spiny) cocci cohering or free from the axis, 

 or capsular and septicidally dehiscent. Seeds usually pendulous and 

 solitary (rarely 2 or more) in each cell, oblong or linear ; raphe 

 adnata or free ; testa membranous, crustaceous or thick and muci- 

 laginous ; albumen scanty (rarely 0); embryo as long as the seed, 

 green, straight or rarely curved ; cotyledons oblong or linear, thick or 

 foliaceous ; radicle short, straight, superior. — Distrib. Tropical and 

 warm regions of both hemispheres ; rare in tropical Africa ; genera 17 ; 

 species about 100. 



Seeds exalbuminous 1 . Tribulus. 



Seeds albuminous. 



Petals 2. Seetzenia. 



Petals 4-5. 



Stameus 12-15 3. Peganum. 



Stamens 8-10. 



Ovules axile ; stipules not spiny 4. Zygophyllum. 



Oyules basal ; stipules spiny 5. Fagonia. 



1. TRIBULUS, Linn. 



Branching prostrate herbs, often with silky hairs. Leaves stipulate, 

 opposite (or sometimes alternate by suppression), usually one of the pair 

 smaller than the other, abruptly pinnate. Flowers solitary, pseudo- 

 axillary, white or yellow. Sepals 5, imbricate. Petals 5, spreading, 

 imbricate, fugacious. Disk annular, 10-Iobed. Stameus 10 (rarely 5), 

 inserted on the base of the disk, the longer opposite to the petals, the 

 5 shorter with a small gland outside ; filaments filiform, naked. Ovary 

 sessile, hirsute, 5-12-lobed, 5-12-celled ; ovules 1-5 in each cell, super- 

 posed ; style short, pyramidal or filiform ; stigmas 5-12. Fruit 

 5-angled, of 5-12 winged or spinous or tuberculate indehiscent cocci. 

 Seeds obliquely pendulous ; testa membranous ; embryo exalbuminous ; 

 cotyledons oval ; radicle short. — Distrib. Warmer regions of the globe; 

 species about 15. 



Cocci witli 2 long and 2 short spines 1. T. terrcstiis. 



Cocci broadly winged 2. T.ahttus. 



1. Tribulus terrestris, Lhm. Sp. Fl. (1753) p. 387. A pro- 

 cumbent herb ; stems and branches pilose ; young parts silky-villous. 

 Leaves opposite, abruptly pinnate, one of each pair usually smaller than 

 the other, sometimes wanting ; stipules lanceolate, hairy ; leaflets 3-6 

 pairs, \-h in. long, oblong, mucronate, sericco-villous with appressed hairs 

 beneath and more or less so on the upper surface, base rounded oblique; 

 petiolules very short, pilose. Flowers axillary or leaf-opposed, solitary ; 

 pedicels J -| in. long, slender, hairy. Se])aLs \ in. long, lanceolate, acute, 

 hairy. Petals § in. long, oblong-obovate ; claw short, hairy. Ovary 

 bristly ; style short, stout ; stigmatic lobes longer than the diameter of 

 the style. Fruit globose, consisting of (usually) 5 hairy or nearly 

 glabrous, often muriculate, woody cocci, each with 2 pairs of hard 

 sharp spines, one pair longer than the other. Seeds several in each 

 coccus, with transverse partitions between them. Fl. B. I. v. 1, p. 423; 

 Dalz. & Gibs, p. 45 ; Boiss. Fl. Orient, v. 1, p. 902; Trim. Fl. Ceyl. 

 V. 1, p. 194; Woodr. in Journ. Bomb. Nat. v. 11 (1897) p. 266; 

 Watt, Diet. Econ. Prod, v. 6, part 4, p, 78. Tribulus Jamir/inosns, Linn. 



