CAOTACE^:. 421 



n stellate or circumscissile manner at the apex, or an indehiscent nut. 

 Seeds 00, rarely definite or even solitary; embryo curved or spiral, 

 on the outside of mealy albumen; radicle next the hilum. Herbaceous 

 or shrubby succulent plants, with opposite or alternate simple leaves. 

 They are found in warm regions chiefly. The greater part of them 

 grow at the Cape of Good Hope. The order has been divided into three 

 sections: 1. Mesembryese, numerous conspicuous petals, many celled 

 capsule, with stellate dehiscence. 2. Tetragonieae, petals 0, fruit woody 

 and indehiscent. 3. Sesuvese, petals 0, capsule with circumscissile de- 

 hiscence. There are 16 known genera, and 440 species. Examples 

 Mesembryanthemum, Tetragonia, Aizoon, Sesuvium. 



Some of them are used as articles of diet, as the leaves of Me- 

 sembryanthemum edule, Hottentot's Fig, and Tetragonia expansa, New 

 Zealand Spinach. Others yield soda, and have been employed in the 

 manufacture of glass. Mesembryanthemum crystallinum, the Ice-plant, 

 is remarkable for the watery vesicles which cover its surface, and which 

 have the appearance of pieces of ice. The seed-vessels of some species 

 of Mesembryanthemum, as M. Tripolium, have the property of expand- 

 ing in a star-like manner when put into water, and closing when dry. 

 The flowers of many of the plants of the order exhibit the pheno- 

 menon of opening only under the influence of sunshine, and closing 

 in dull weather (f 483). 



882. Order 92. Cactacete, the Cactus or Indian Fig Family. (Poly- 

 pet. Epigyn.) Sepals numerous, usually co , and confounded with the 

 petals, adherent to the ovary. Petals numerous, usually indefinite, 

 sometimes irregular, inserted at the orifice of the calyx. Stamens 

 indefinite, cohering more or less with the petals and sepals; filaments 

 long, filiform; anthers ovate, versatile. Ovary fleshy, inferior, unilo- 

 cular; style filiform ; stigmas numerous; ovules GO , attached to parietal 

 placentas equal in number to the stigmas. Fruit succulent, 1 -celled. 

 Seeds co , parietal, or, after losing their adhesion to the placenta, nest- 

 ling in pulp, ovate or obovate; albumen 0; embryo straight, curved 

 or spiral; cotyledons thick, leafy, sometimes nearly obsolete; radicle 

 thick, obtuse, next the hilum. Succulent shrubs, with peculiar angu- 

 lar or flattened stems, having the woody matter often arranged in 

 wedges. Leaves usually absent; when present, fleshy, smooth, entire, 

 or spinous. Flower sessile, sometimes showy. They grow in hot, 

 dry, and exposed places, and are natives chiefly of the tropical parts 

 of America. Some grow rapidly on the lava in volcanic countries. 

 There are 16 known genera, and about 800 species. Examples 

 Opuntia, Melocactus, Mammillaria, Echinocactus, Cereus, Epiphyllum, 

 Pereskia, Rhipsalis. 



883. 'The plants of this order are remarkable for their succulence, 

 for the great development of their cellular tissue, and the anomalous 

 forms of their stems, some of which attain a great size. In their struc- 



