550 



SYSTEMATIC BOTANY. 



several. Fruit succulent. Seeds numerous, parietal, or im- 

 bedded in the pulp, without albumen. 



Fig. 933. 



Fig. 934. 



Fig. 933. Vertical section of the flower 

 of the Prickly Pear (O/JUntia vul- 

 garis) Fig. 934. Diagram of the 



flower of Opuntia vulgaris. 



Distribution, Sfc. — Natives exclusively of the tropical regions 

 of J^merica. Examples: — Melocactus, Mammillaria, Echino- 

 cactus, Pilocereus, Cereus, Ei)iphyllum, Khipsalis, Opuntia, 

 Pereskia. There are 18 genera, and about 800 supposed 

 species. 



Properties and Uses. — The fruit of many species is somewhat 

 acid and agreeable, and is useiul in febrile complaints. The 

 fleshy stems of the Melon Cactus {Melocactus), are eaten by 

 cattle on account of their juice, in the dry districts of South 

 America. Many species of Cereus, Epiphyllum, Phyilocactus, 

 Sec, are cultivated on account of their showy flowers. Some 

 species of Cereus open their flowers at night; some of the flowers 

 have been measured 1 foot in diameter. 



Opuntia vulgaris The fruit of this pl.int is the Prickly Pear, which is 



miRli eaten in Americiiand the South of Europe, and has been lately imported 

 into this country. Tlie fruit of (). Tuna is of a carmine colour, and has been 

 employed as a water-colour. O. cochinilUJera, the Nopal Plant, is cultivated 

 in Mexico, kc, for llie nourishment of the Cochineal Insect (Coccus Cacti). 



^Natural Order 103, GROSSDLARiACE.a:. — The Gooseberry or 

 Currant Order. — Shrubs, with {Jig. 361), or without spines 

 or prickles. Leaves alternate, lobcd, radiate-veined. Flowers 

 axillary, racemose, perfect or rarely unisexual. Calt/x su])erior, 

 4 — 5 lobed. Petals 5, minute, and inserted on the calyx. 

 Stamens 5, inserted on the calyx, and alternate with the 

 petals. Of ary inferior, 1 -celled with 2 parietal placentas (yigr. 



