Key to the Families vii 



'Calyx present; corolla wanting. 



Pistil 1, 1-celled, 1-ovuled. 

 Stipules present. 

 Leaves alternate. 



Stipules not sheathing. 



Flowers monoecious ; herbage with stinging hairs. 



UBTICACEAE, 106. 

 Flowers perfect, fascicled; diminutive annual. 



ALCHEMILLA, 203. 

 Stipules sheathing; calyx usually 6-parted, often petaloid. 



POLYGONACEAE, 110. 



Leaves opposite, pungent; petals represented by minute scales. 



PENTACAENA, 150. 

 Stipules none. 



Calyx petaloid. 



Calyx 6- (rarely 5-) parted; seed a 3-sided or lenticular achene. 



POLYGONACEAE, 110. 

 Calyx tubular, its base hardening and enclosing the achene. 



NYCTAGINACEAE, 136. 

 Calyx not petaloid. 



Sepals herbaceous; herbage more or less succulent and scurvy. 



CHENOPODIACEAE, 123. 

 Sepals membranous or scarious; flowers with bractlets. 



AMARANTHACEAE, 132. 



Pistils several, distinct, each 1-celled, 1-ovuled. THALICTRUM, 156. 

 Pistil 1, 3-5-celled; sepals sometimes petaloid; flowers perfect. 



AIZOACEAE, 138. 



Pistil 3-celled; flowers dioecious or monoecious. EUPHORBIACEAE, 231. 

 Pistil 1, 10-celled; fruit a berry. PHYTOLACCACEAE, 135. 



2. TREES AND SHRUBS. 



Leaves opposite. 



Flowers dioecious; low maritime shrub; leaves fleshy. 



BATIDACEAE, 134. 

 Flowers perfect or dioecious; sepals petaloid; fruit a tailed achene. 



CLEMATIS, 154. 



Flowers perfect ; fruit a samara. FRAXINUS, 302. 



Xeaves alternate. 



Flowers perfect; sepals petaloid. 

 Sepals 6; stamens 9. 



Stamens opening by uplifted valves; aromatic tree. 



LAURACEAE, 157. 

 Stamens splitting longitudinally; shrubs. 



ERIOGONUM, 116. 



Calyx 5-cleft; stamens 5, monadelphous. FREMONTODENDRON, 250. 

 Flowers monoecious in head-like clusters. PLATANACEAE, 194. 



Flowers perfect or unisexual ; sepals and stamens 4 or 5; fruit berry-like. 



RHAMNUS, 241. 



