478 



ZYGOPHYLLACE^. 



[Hypogynous Exogkns. 



Order CLXXX. ZYGOPHYLLACEiE.— Beancapers. 



Zygophylleae, R. Brow7i in Flinders, (1814); DC. Prodr. 1. 703. (1824); Adrien de Juss. Rutacees, 67. 

 (1825); Endl. Gen. ccliii.— Melianthes, Endl. p. 1165. 



Diagnosis. — Rutal Exogens, with fe^o-seeded finally apocarpov^ fruit, whose pericarp does 

 not laminate, a dry inconspicuous too^us, albuminous seeds, and opposite leaves 



icithout stip)ules. 



Herbaceous plants, shrubs, or trees, vA\h a very hard wood, the branches often arti- 

 culated at the joints. Leaves opposite, with stipules, vei'y seldom simple, usually 

 vmequally pinnate, not dotted. Flowers sohtary, or in 

 pau's or threes, white, blue, or red, often yellow, herma- 

 phrodite, regular. Calyx di\aded into 4 or 5 pieces, -ndth 

 convolute aestivation. Petals unguiculate, alternate mth 

 the segments of the calyx and a little longer, in sestivation, 

 which is imbricated, at first very short and scale-hke. Sta- 

 mens double the number of the petals, dilated at the base, 

 sometimes naked, usually placed on the back of a small scale, 

 hypogjTious. Ovary simple, suiToimded at the base with 

 glands or a short sinuous disk. More or less deeply 4- or 5- 

 furrowed, with 4 or 5-cells ; OAOiles in each cell 2 or more, 

 attached to the inner angle, pendulous, or occasionally erect ; 

 style simple, usually with 4 or 5 furrows ; stigma simple, or 

 with 4 or 5 lobes. Fruit capsular, rarely somewhat fleshy, 

 with 4 or 5 angles or ^^ings, bursting by 4 or 5 valves beai'- 

 ing the dissepiments in the middle, or into as many close 

 cells ; the sarcocai'p not separable from the endocarp. Seeds 

 usually fewer than the ovules, either compressed and scabrous 

 when dry, or ovate and smooth, with a thin herbaceous 

 integument. Embryo green ; radicle superior ; cotyledons 

 fohaceous ; albumen in small quantity, wliitish, between 

 horny and cartilaginous, in Tribulus wanting. 



These plants are remarkable in the Rutal Alliance for 

 their opposite leaves and conspicuous stipules. With 

 Quassiads they other\\dse accord in the stamens springing 

 from the back of a hypogynous scale. Adrien de Jussieu 

 also observes that the petals are remarkable for their being, 

 in an early state, minute and hidden by the calyx, which 

 they only exceed about the time of flowering, while in other 

 Rutal Orders the petals are always larger than the calyx. 

 The distmguishing characters in the vegetation or habit of 

 this Order are not only the leaves being constantly opposite, 

 \\\t\\ lateral or intennediate stipules, but also in theu' being 

 generally compound, and always destitute of the pellucid 

 glands which miiversally exist in true Rueworts. For this 

 reason the genus Biebersteinia must be excluded, although 

 its leaves have stipules. It is also a very common character of the Order to have the 

 radicle at that extremity of the seed which is most remote from the hilum ; but this, 

 which is of great importance in many natm'al famihes, is of less value in Eeancapers. 

 (See many good remarks upon this subject in Brown's Appendix to Denham, p. 27.) 

 An anonymous author expresses his opinion (lAnncea, xv. 249.) that the true affinity 

 of this Order is ^\'ith Oxalids, not Rueworts. He would not however keep them in the 

 neighbom-hood of CranesbiUs, but thinks Mallowworts theu' true relations. 



Guaiacum, Porheria, and LaiTea, are peculiar to America. Fagonia is distributed 

 over the south of Em'ope, the Levant, Persia, and India. Zygophyllum inhabits the 

 same regions, and also the south of Africa, and is represented in New Holland by 

 Ropera. Tribulus occurs in all the Old World withm the tropics, or in countries bor- 

 dering upon them. MeUanthus, a most anomalous genus, is remarkable for being 

 foimd both at the Cape of Good Hope and in Nipal, without any intermediate station. 

 The abundance of Beancapers constitutes one of the most striking features of the 

 vegetation of the Egyptian deserts. 



Fig. CCCXXXI. 



Fig. CCCXXXI. 

 5. section of a seed. 



-Ropera fabagifolia. 



flower ; 2. pistil ; 3. perpendicular section of it : 4. fruit ; 



