KEY TO FAMILIES. 11 



Leaves not reniform or cordate. 



Calyx-lobes 4. 



Leaves alternate; fruit a 3 to 9-eelled bony nut -with herbaceous cover- 

 ing ; succulent herb Tetragoxia, p. 150. 



Leaves opposite; fruit a 4-celled capsule; stems creeping in mud or 



floating in water Ludwigia, p. 273. 



Calyx entire; stamens 1; fruit nut-like, 1-celled, 1-seeded; aquatics with 

 simple entire leaves in whorls Hippuris, p. 284. 



II. CHORIPETALOUS DIVISION. Calyx and corolla present; petals dis- 

 tinct or nearly so. 



A. Ovary superior, i.. e., free from the calyx. 

 1. Flowers with the stamens monadelphqus or diadelphous. 

 Flowers papilionaceous (1 petal in Amorpha) ; ovary 1-celled; stamens 10, 

 united in 1 or 2 sets (distinct in Pickeringia) ; leaves compound (simple 



in Cercis) Legumixosae, p. 214. 



Flowers not papilionaceous. 



Corolla irregular, the petals 4, in 2 dissimilar pairs; sepals 2; stamens 6, 



slightly united in 2 sets; leaves compound Dicextra, p. 178. 



Corolla regular; petals 5; sepals 5. 



Stamens 10, more or less united at base; leaves 3-foliolate 



Oxalidaceae, p. 241. 



Stamens numerous, united in a tube around the pistil; leaves simple 



Malvaceae, p. 257. 

 2. Flowers with the stamexs distixct. 



a. Stamens Iti/pogynous, more titan 10. 

 Pistils several to many, simple and distinct. 



Leaves not peltate. 



Pistils becoming achenes or follicles Eaxuxculaceae, p. 164. 



Pistils at first united, later distinct as torulose pods 



Platystemox, p. 175. 



Leaves peltate; aquatic plant Brasexia, p. 164. 



Pistil 1. 



Ovary 1-celled, the styles or stigmas often more than one. 



Sepals caducous ; petals 4 or 6, twice as many as the sepals 



Papaveraceae, p. 174. 

 Sepals persistent or at least not caducous. 



Acaulescent plants; petals 8 to 16; sepals 4 to 8. . . .Lewisia, p. 159. 

 Caulescent plants. 



Petals 5; fruit a capsule; leaves simple, entire. 



Sepals 2; styles •"- Calandbinia, p. 150. 



Sepals 5, the 2 outer smaller and bract-like; style 1 



Cistaceae, ]». 265. 



Petals 1 or 2; sepals about 4; fruit a berry; leaves compound 



Actaea, p. 167. 

 Ovary more than L-celled. 



Petals 5; sepals 5; stamens disposed in :; to 5 Lndistincl hunches; Leaves 



opposite Hyfebjcaceae, p. 262. 



Petals 10 to 20; sepals 5 to 12; aquatic herbs Nymphaea, p. 103. 



b. Stamens hypogynous, L0 or }<<r<\\ 

 Pistils more than 1, distinct, ami 



Exceeding in number the sepals or petals RantjNCUIACEAE, p. 164. 



