CHAP. I.] GENTIANE^. 403 



ORDER CXXVIIT.— ASCLEPIADE^. 

 These plants are very nearly allied to the 

 last, and they differ chiefly in having the seg- 

 ments of their corollas straight, in their stamens 

 being united into a sort of crown, and in their 

 pollen being found in masses of a waxy sub- 

 stance. The seeds are also each furnished with 

 a tuft of fine long silky hair. The principal 

 plants are Periploca grceca^ a hardy, climbing, 

 shrub, with rich, dark, velvet-looking flowers, 

 which are said to be poisonous to flies, and Hoya 

 carnosa, a stove or greenhouse climber, with 

 waxen- looking, clustered, odoriferous flowers, 

 distilling honey ; to these may be added Pergu- 

 laria, a stove climber, remarkable for its fra- 

 grance, Physianthus, Gonolobus, Ceropegia, and 

 Asclepias, all singular-looking climbing plants ; 

 and besides these, I may mention Stapelia, the 

 species of which are dwarf plants, with their 

 flowers hanging down below the pots in which 

 they grow, and the odour of which is so like 

 that of carrion, as to induce flesh-flies to lay 

 their eggs upon them. 



ORDER CXXIX.-GENTIANEJE.— THE GENTIAN- 

 TRIBE. 



The best known genera are Gentiana, (the 

 Gentian), Lisianthus, and Menyanthes (the 



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