WESTERN MIDDLE CALIFORNIA. 



9 



Calyx 4-parted; diminutive annual with filiform leaves. . 



Sagina apetala, p. 169. 



Calyx and corolla both wanting; pistil 1. 

 Flowers perfect, borne in a spike, each flower subtended by a 

 colored bract, the spike subtended by a conspicuous colored 

 involucre; herb of saline habitat . Anemopsis, p. 162. 

 Flowers monoecious. 

 Terrestrial plants; flower-clusters often surrounded by a petal- 

 like involucre resembling a perianth; stamens 1 to many; 

 capsule 1 or commonly 3-celled; juice often milky .... 



ElJPHORBIACE.E, p. 260. 



Aquatic plants; leaves opposite; stamens 1. 

 Leaves dissected; ovary 1-celled, in fruit a spinose or tubercu- 



late achene Ceratophyllace^e, p. 191. 



Leaves entire; ovary 4-celled, splitting when ripe into 4 parts. 



Callitrichace.e, p. 263. 



** Ovary inferior, x. e., more or less adherent to the calyx. 



Flowers dioecious or the pistillate with stamens; stamens many; cap- 

 sule 1-celled; leaves alternate, divided 



Datiscace.e, p. 321. 



Flowers perfect. 



Leaves reniform or cordate; calyx-lobes 3, caudate; capsule 6-eelled: 



nearly acauiescent perennial . . . Asarum, p. 363. 

 Leaves not reniform or cordate. 

 Calyx-lobes 4. 



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



covering; succulent herb . . Tetragonia, p. 189. 

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

 mud or floating in water . . Ludwigia, p. 326. 

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



aquatics with simple entire leaves in whorls 



Hippuris, p. 838. 



II. CHORIPETALOUS DIVISION. Calyx and corolla present, 

 the latter of distinct petal*. 



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



I. Stamens hypogynous, more than 10. 



Pistils several to many. 



Pistils simple and distinct. 

 Leaves not peltate. 



Pistils becoming achenes or follicles 



Kanunculace^e, p. 193. 



Pistils at first united, later distinct as torulose pods 



Platystemon, p. l2(>">. 

 Leaves peltate; aquatic plant . . . Brasenia, p. 192. 

 Pistils cohering in a ring around a central axis; stamens monadel- 

 phous Malvaceae, p. 236. 



