THE WAX-FLOWEK FAMILY. 239 



ones, as happens also in the wild Guelder-rose. Occasionally all the 

 flowers are sterile and enlarged, and then, instead of a simple circle 

 or border of such, there is a dense globular mass, like that of the 

 Guelder-rose when cultivated. This at least is the case in the com- 

 mon species or Hydrangea hortensis, which is fi'equent both in pots in 

 houses, and as a shrub in warm borders under walls. The flowers 

 are either pink or blue. To the same family belong the Adamia and 

 the Bauera rubioides. 



LXX.— THE WAX-FLOWER FAMILY. Asclepiaddcece. 



A large family of very extraordinary plants, having its maximum 

 in the southernmost part of Africa, where vast numbers of the succu- 

 lent species occupy the plains and other dry and sterile places. They 

 abound also in tropical India and New Holland, and in the equinoctial 

 parts of America. They are mostly shrubs, almost always milky- 

 jmced, and often twining, with entire, usually opposite leaves ; flowers 

 usually umbellate, the umbels arising from between the petioles of 

 the leaves ; and very elegantly symmetrical, pentamerous flowers, 

 distinguished from those of the Convolvulus, Periwinkle, and Potatoe 

 families, to which they are in many respects allied, by having the 

 anthers and stigma consolidated. These parts are not merely in close 

 contact, but actually consolidated into a single body, the centre of 

 which is occupied by the broad disk-like stigma, the grains of pollen 

 cohering in the shape of waxy bodies attached finally to the five 

 comers of the stigma, and adhering to it by the intervention of j^ecu- 

 liar glands. The ovaries are two, ripening into a pair of follicles, 

 with numerous seeds, which are almost always covered with long 

 white hairs. 



Being altogether foreign, and mostly tropical, the family is repre- 

 sented near Manchester only in the conservatory. The best known 

 species is the wax-flower, or Hoya carnosa, its long semi-twining 

 stems provided with abundance of thick, oval, pointed, leathery leaves, 

 and profusion of di'ooping and sessile umbels of whitish-pink flowers, 

 each with a hard and shining pink star in the centre, moulded, to 

 appearance, out of the finest porcelain, and a gem of transparent 

 honey depending from it like a drop of dew. Next in frequency 

 is the magnificent white-flowered Stephanotus, which seems to grow 

 in natural chaplets ; and along with it several smaller Hoyas, and 



