EANUNCULACEAE. 119 



Flowers perfect or monoecious, if dioecious on neither vines nor lierbs : with 

 simple leaves. 

 Plants with minute axillary monoecious flowers : anthers with horn- 

 like appendages. Fam. 1. Ceiwtopiiyllaceae. 

 Plants with perfect or rarely dioecious flow- 

 ers : anthers not with horn-like appendages. 

 Carpels one or more, distinct at least at 

 maturity. 

 Sepals 3-15 : petals about as many : 

 plants if shrubby not with pulpy 



fruit : endosperm even. Fam. 2. Ranunculaceae. 



Sepals 3 : petals 6 : fruit pulpy : endo- 

 sperm channeled. Fam. 3. Annonaceae. 

 Carpels more or less coherent or united 

 into cone-like structures, or immersed 

 in the pulpy receptacle. 

 Sepals valvate. Fam. 3. Annonaceae. 

 Sepals imbricate. Fam. 4. Magnoliaceae. 

 Flowers dioecious : vines with simple leaves. Fam. 5. Menispeemaceae. 

 Water plants : emersed or floating leaves with pel- 

 tate blades. 

 Carpels several and distinct. Fam. 6. Cabombaceae. 

 Carpels united into compound pistil. Fam. 7. Nympiiaeaceae. 

 Stamens few and definite, the anther-sacs opening by 



hinged valves except in Podophyllum. Fam. 8. Podopiiyllaceae. 



Family 1. CERATOPHYLLACEAE. Hornwort Family. 



Annual aquatic herbs. Leaves whorled : blades cleft or finely dis- 

 sected. Calyx of 6-12 narrow toothed or cleft sepals. Coi'olla wanting. 

 Androecium of 10-24 stamens with short filaments. Gynoeeium 1-carpel- 

 lary : stigma subulate. Fruit an aohene, sometimes spine-armed. 



1. CEKATOPHYLLUM L. Submerged plants with sessile leaf-blades, 

 the divisions mostly thrice forked. 



1. C. demersum L. Stems 3-12 dm. long: leaves rather rigid; blades 1-2- 

 times forking: sepals oblong to ovate-oblong, erose: stamens slightly exserted: 

 style and stigma exserted : achenes 5 mm. long. — Susquehanna valley. Eare, 

 in shallow water. — Sum. — Hornwort. 



Family 2. RANUNCULACEAE. Crowfoot Family. 



Herbs or woody vines. Leaves alternate (opposite in Clematideae) : 

 blades simple or compound. Calyx of 3-5 distinct, imbricate sepals (val- 

 vate in Clematideae) . Corolla of about as many petals as there are sepals, 

 occasionally more, or wanting. Androecium of several or many hypogy- 

 nous stamens. Gynoeeium of 1, several, or many distinct carpels. Finiit 

 an achene or a follicle, or baccate. 



Fruit a follicle or a berry : carpels with several ovules, or with only 1 or 2 ovules 

 in Hydrastis. 

 Flowers regular. 



Leaf-blades palmately nerved or palmately compound. 



Fruit baccate : sepals inconspicuous, fugaceous. 1. Hydrastis. 



Fruit follicular : sepals conspicuous, persistent during 



anthesis. 2. Caltha. 



' Leaf-blades pinnately or ternately compound or decom- 

 pound. 

 Petals without spurs, or wanting. 



Fruit dry follicles : racemes elongate. 3. Cimicifuga. 



Fruit berry-like follicles : racemes short. 4. Actaea. 



Petals prolonged backward into hollow spurs. 5. Aquilegia. 



Flowers irregular, the posterior sepal, and posterior petals, 



spurred. G. Delphinium. 



Fruit an achene : carpels with a single ovule each. 



Flowers, or their pedicels or peduncles, subtended by invo- 

 lucres. 

 Involucre close under the calyx : bracts entire. 7. Hepatica. 



