23 



216. Ovule in the females or stamens 



in the males enclosed in an 

 ovoid perianth ; leaves oppo- 

 site 

 Ovules not in ovoid perianth 



217. Ovules and seeds in pairs under 



the scales of a cone, leaves 

 alternate, or clustered and sub- 

 ulate ... 

 Ovules on the teeth of leaflike 

 organs... 



218. Ovary 1-ceUed, or if 2-ceUed with 



1 ovule in each cell ... 

 Ovary with 2 (many ovuled) or 

 more cells 



219. No perianth, at least in the female 



flower... 

 Perianth herbaceous 



220. Female flowers forming a prickly 



2-ceIled burr, with 2 conical 

 pointed styles 

 Flowers not forming burrs 



221. Flowers minute, crowded inside 



or outside of succulent recep- 

 tacles ... 

 Flower receptacles not fleshy 



222. Flowers in catkins 



Flowers crowded in cylindrical 

 leaf - opposed pedunculate 

 spikes 



223. Styles 2 



Styles 1 ... 



224. Stigmas 3- to 5-lobed ; shrub . . . 

 Style entire or 2-lobed ... 



225. Leaver alternate ; flowers in spikes 



or catkins 

 Leaves opposite ; flowers in 

 axilliary clusters 



226. Fruit 1-seeded 



Fruit of 2 cells or cocci 



227. Ovary 2-ceUed,with several ovules 



in each cell ; flowers in globu- 

 lar or ovoid heads ; tree 

 Ovary 3- or more-celled, or if 2- 

 celled, with 2 ovules in each... 



228. Ovary 5-lobed ; fruit follicular ; 



tree with paniculate flowers 

 Ovary entire 



229. Ovary usually 3-celled, rarely 2- 



or several-celled ; fruit divid- 

 ing into cocci, or baccate ; 

 shrub or tree ; seeds albu- 

 minous 



Gnetaceae (p. 255). 

 217. 



Coniferae (p. 255). 

 Gycadaceae (p. 256). 

 219. 



227. 



220. 

 223. 



Compositae (p. 135). 

 221. 



Urticaceae (p. 241). 



222. 

 Myricaceae (p. 251). 



Piperaceae (p. 220). 

 Hamamelidaceae (p. 100). 



224. 



225. 



226. 



Euphorbidceae (p. 230). 



Santalaceae (p. 229). 

 Urticaceae (p. ). 

 Eupkorbiaceae (p. 230). 



Hamamelidaceae (p. 100). 



228. 



Sterculiaceae (p. 49). 

 229. 



Eupkorbiaceae (p. 230), 



