Tribulus.'] XXXI. zygoprylle^ (oliver). 285 



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

 I.e.). 



Upper Guinea. Cape Coast, 71 Voqel ! 

 Chiefly coiitiiied to tropical America. 



2. ZYGOPHYLLUM, Linn. ; Benth. ct Hook. f. Gen. PI. i. 266. 



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

 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.) . \. Z. simpler. 

 Leaves orbicular to obovate, 1-2^ in. broad. Staniinal scale fimbri- 

 ate. Fruit deeply wiuged, ^-f 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. Z. simplex, Linn.; DC. Prod. i. 705. A much-branched, diflfuse, 

 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 ^ 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 Ijand. Nubia, Ehrenberg^ and other provinces of Nile Land {SchKeinf. et Asch. 

 Enum.). 



Ijower Guinea. Benguella, Br. Curror ! Bengnella and Mossamedes, (a fine wrio 

 of varying forms), Dr. Welwitsch ! 



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



2. Z. orbiculatum^ TFelw. mss. Glabrous, glaucous, shrubby below, 

 with oblique or ascending, succulent, terete branches, attaining l-l^ ft. 

 Leaves 1-foliolate ; leaflets plane, thickly fleshy, flabelhite-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. Petflls wliiic, 

 twice as long as the obtuse sepals ; apex rotundatc, denliculate. Staminal 

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

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



