Tribulus.] XXXI. ZYGOPHYLLE.E (OLIVER). 285 



Hook. f. Fl. Nigrit. 269. T. pubescent, Don, Gen. Syst. i. 769 (ex Hook. f. 

 1. c). 



Upper Guinea. Cape Coast, T. Vogel ! 

 Chiefly confined to tropical America. 



2. ZYGOPHYLLUM, Linn. ; Benth. et Hook. f. Gen. PL i. 266. 



Sepals 5 or 4, persistent or deciduous. Petals as many, unguicuJate. 

 Stamens 10-8 ; filaments filiform, with a minute scale at the base; anthers 

 small. Ovary sessile, 5-4-gonous, 5-4-celled ; style subulate or filiform ; 

 stigma minute. Ovules 2 or more. Fruit lobed, angled or winged, inde- 

 hiscent or separating into as many cocci as carpels or loculicidally dehiscent. 

 Seeds albuminous. — Frutescent herbs or shrubs, erect or prostrate, often 

 spinose. Leaves opposite, 1-2-foliolate, often fleshy. Stipules 2. Pedun- 

 cles solitary or geminate. 



A considerable Old World genus, most numerous in extratropical Africa, Australia, and 

 the deserts of western Asia. 



Leaves simple. 



Leaves cylindric-clavate to obovate-oblong, 2-6(-12) lines long. 



Stamiual scale 2-fid. Fruit obovoid, 1-2 lines long. (Annual.) . 1. Z. simplex. 

 Leaves orbicular to obovate, l-2£ in. broad. Stamiual scale fimbri- 

 ate. Fruit deeply winged, £-£ in. diam 2. Z. orbiculatum. 



Leaves 1 -jugate. 



Papillose or hoary. Staminal scale entire. Fruit obcordate . . 3. Z. album. 

 Glabrous. Staminal scale entire. Fruit clavate-prismatic . . . 4. Z. coccineum. 

 Glabrous. Staminal scale 2-fid. Fruit turbinate 5. Z. decumbent. 



1. 2. simplex, Linn.; DC. Prod. i. 705. A much-branched, diffuse, 

 decumbent or ascending, rarely erect annual, or frutescent below and perhaps 

 biennial. Leaves of each pair 1-foliolate, unequal ; the larger from 2-3 lines 

 to i in. or more, fleshy, cylindric-clavate or flattened oblanceolate to obovate- 

 oblong, obtuse. Peduncles very short, not exceeding the small yellow flowers, 

 deflexed in fruit. Scales at the base of the filaments 2-partite. Fruit deeply 

 5-lobed, more or less broadly obovoid, about 1-1| line long. 



Nile Land. Nubia, Ehrenberg, and other provinces of Nile Land [Schweinf. et Asch. 

 Enum.). 



Lower Guinea. Benguella, Dr. Curror ! Benguella and Mossamedes, (a fine scries 

 of varying forms), Dr. Welwitsch ) 



From Cape Verde Islands, eastward through North Africa to Scinde. Also at the Cape. 



2. Z. orbiculatum, Weho. mss. Glabrous, glaucous, shrubby below, 

 with oblique or ascending, succulent, terete branches, attaining 1-1 £ ft. 

 Leaves 1-foliolate ; leaflets plane, thickly fleshy, flabel late-orbicular or ob- 

 ovate-spathulate, entire, shortly and cuneately contracted into the petiole, 

 glabrous, often 2-2 £ in. broad. Stipules fleshy, ovate, obtuse, |-| in. 

 Peduncles 2-3 together, 3-5 lines long, at length nearly 1 in. Petals white, 

 twice as long as the obtuse sepals ; apex rotundate, denticulate. Staminal 

 scale fimbriate at the apex. Fruit broadly 5-winged, depressed, obovoid, 

 subemarginate, 7-8 lines in diam. ; wings strongly reticulate. 



