II.] K'EY TO NATURAL ORDERS. 141 



maphrodite or unisexual flowers. Stamens when equalling 

 lobes of perianth in number, opposite to them. Ovary 

 superior, one-celled, with a solitary ovule. Seed albuminous, 

 with a curved embryo. 



Amarantace^ (p. 268). — Herbs or shrubs {Dccriugia) 

 with opposite or alternate exstipulate leaves and minute 

 scarious hermaphrodite or unisexual flowers. Stamens 

 usually five. Ovaiy superior, one-celled, with one ovule, or 

 several ovules on a central placenta. Seeds albuminous, 

 with a curved embryo. 



PoLYGONACE/E (p. 269). — Hcrbs or shrubs with alternate 

 simple leaves and sheathing stipules, and small greenish 

 or coloured hermaphrodite or unisexual flowers. Ovary 

 superior, with a soHtary erect ovule ; stigmas two or more. 

 Seeds albuminous, with a straight or slightly curved 

 embryo. 



Urticace^ (p. 270). — Trees, shrubs, or herbs with usually 

 alternate stipulate leaves and minute herbaceous unisexual 

 flowers. Stamens as many as perianth-segments, and oppo- 

 site to them. Ovary free. Fruit one-seeded. 



EuPHORBiACE^ (p. 276). — Trees, shrubs, or herbs with 

 unisexual flowers. Ovary free, three-celled, with one or two 

 pendulous ovules in each cell. Seeds albuminous. 



Aristolochiace/E (p. 281).— Climbing shrubs or herbs 

 with alternate leaves, and usually an irregular perianth, 

 valvate in bud. Ovary inferior, three- to six-celled ; ovules 

 indefinite. 



Nepenthace^ (p. 281).— Climbing shrubs with alternate 

 pitcher-bearing leaves, and racemose dioecious flowers. 



Salicace^ (p. 282). — Trees or shrubs with alternate 

 leaves, and dioecious amentaceous flowers. Perianth o, or 

 rudimentary. Ovary free, one-celled ; ovules indefinite, 

 basal 01 parietal. 



