KEY TO THE ORDERS. XXI 



URTICACE^. Herbs. Stigma 1. Flowers monoecious or 

 dioecious, in spikes or racemes. No chaff-like bracts 

 among the flowers. Or, Stigmas 2 ; leaves pal- 

 mately-compound 198 



ILLECEBRACE.E. Herbs, small, tufted. Flowers greenish 

 or whitish, terminal. Stamens as many as the 

 divisions of the 5-parted calyx and opposite them, 

 or fewer, perigynous. Sepals hooded at the top 

 and bristle-pointed. Style 2-cleft 183 



AMARANTACE^E. Herbs. Flowers greenish or reddish, in 



spikes, with chajf-like bracts interspersed. Stigmas 2. 187 



CHENOPODIACE.E. Herbs. Flowers greenish, in spikes. 



No chaff-like bracts. Stigmas 2 184 



OLEACE.E. Trees. Leaves pinnately compound. Fruit a 1- 



seeded samara 181 



URTICACE.E. Trees. Leaves simple. Fruit a 1 -seeded sa- 

 mara winged all round, or a drupe 198 



LAURACE^E Trees or shrubs. Flowers dioecious. Sepals 6, 



petal-like. Stamens 9, opening by uplifting valves. 193 



THYMELEACE.E. Shrubs with leather-like bark, and jointed 

 branchlets. Flowers perfect, preceding the leaves. 

 Style thread-like 194 



B. Flowers in catkins. 



* Sterile or staminate flowers only in catkins. 



JUGLANDACE.E. Trees with pinnate leaves. Fruit a nut 



with a husk 202 



CUPULIFER^E. Trees with simple leaves. Fruit one or 

 more nuts surrounded by an involucre which 

 forms a scaly cup or bur 204 



* * Both sterile or fertile flowers in catkins, or catkin-like heads. 



SALICACE^E. Shrubs or low trees. Ovary 1-celled, many- 

 seeded ; seeds tufted with down at one end 209 



PLATANACE.E. Large trees. Stipules sheathing the branch- 

 lets. The flowers in heads 201 



MYRICACE^E. Shrubs with resinous-dotted, usually fra- 

 grant, leaves. Fertile flowers one under each 

 scale. Nutlets usually coated with waxy grains . . 203 



BETULACE.E. Trees or shrubs. Fertile flowers 2 or 3 under 

 each scale of the catkin. Stigmas 2, long and 

 slender 207 



