KANUNCULACEAE 



429 



1. Ceratophyllum submSrsum L. Stems 3-4 dm. long. Leaves flaccid, several in 

 a whorl ; blades three to four times forking, the segments filiform, bristly-toothed : achenes 

 oblong, slightly flattened, 4 mm. long, unarmed, sparingly warty, the rounded edges un- 

 armed. 



In ponds, southern peninsular Florida. 



2. Ceratophyllum demersum L. Stems 3-12 dm. long, branching. Leaves rather 

 rigid, 6-9 in a whorl, 1-2 cm. long ; blades once or twice forking, the ultimate segments 

 spiny-toothed : achenes oblong, slightly flattened, 5 mm. long, each tipped with the per- 

 sistent style and armed with a spreading spine on either side at the base. 



In ponds and still water, throughout North America except the extreme north. 



3. Ceratophyllum echinatum A. Gray. Stems 2-5 dm. long, branching. Leaves 

 flaccid, 9-12 in a whorl, 1.5-2.5 cm. long ; blades three to four times forking, the ultimate 

 segments bristly-toothed : achenes oval, 5-6 mm. long, flattened, each tipped with the 

 persistent style, the faces warty, the slightly winged edges fringed with spreading spines. 



In slow streams and ponds, throughout the United States and southern British America. 



FAMILY 2. RANUNCULACEAE Juss. CKOWFOOT FAMILY. 



Annual or perennial herbs, or rarely climbing shrubs, with an acrid sap. 

 Leaves alternate (except in the CLEMATIDEAE) : blades simple or compound. 

 Stipules wanting, but the base of the petiole often clasping or sheathing. 

 Pubescence, when present, composed of simple hairs. Calyx of 3-15, generally 

 caducous often petal-like sepals, imbricated (except in the CLEMATIDEAE). 

 Corolla of about as many petals as there are sepals, occasionally more, or want- 

 ing. Flowers regular or irregular. Stamens several or numerous, hypogynous, 

 their anthers innate. Carpels numerous, or rarely solitary, 1-celled, 1-many- 

 ovuled. Ovules auatropous. Fruit an achene, follicle or berry. Seed with en- 

 dosperm. 



Fruit a follicle or a berry : carpels with several ovules or with only 1 or 2 ovules in genera Nos. 1 and 4 . 

 Flowers regular. 



Leaf-blades palmately nerved or palmately compound. 

 Petals wanting. 



Carpels ripening into a head of red berries. 1. HYDRASTIS. 



Carpels ripening into a head of dry follicles. 2. CALTHA. 



Petals present. 3. HELLEBORUS. 



Leaf-blades pinnately or ternately compound or decompound. 

 Petals without spurs or wanting. 

 Fruit dry follicles. 



Shrubs. 4. XANTHORRHIZA. 



Herbs. 



Low herbs, with solitary or few loosely panicled flowers. 



Carpels and follicles stalked. 5. COPTIS. 



Carpels and follicles sessile. 6. ISOPYRUM. 



Tall herbs, with numerous flowers in strict, simple or branched 



racemes. 7. CIMICIFUGA. 



Fruit berry-like follicles. 8. ACTAEA. 



Petals prolonged backward into hollow spurs. 9. AQUILEGIA. 



Flowers irregular. 



Posterior sepals prolonged into a spur. 10. DELPHINIUM. 



Posterior sepals more or less helmet-like. 11. ACONITUM. 



Fruit an achene : carpels with a single ovule each. 



Flowers, or their pedicels or peduncles, subtended by involucres. 



Involucre close under the calyx ; bracts entire. 12. HEPATICA. 



Involucre remote from the calyx ; bracts toothed, divided or compound. 



Styles subulate : leaf-segments sessile. 13. ANEMONE. 



Styles wanting : leaflets stalked. 14. SYNDESMON. 



Flowers not subtended by involucres. 

 Leaves opposite : sepals petal-like. 

 Petals wanting. 



Stamens spreading : sepals spreading. 



Sepals with scarcely any border : flowers dioecious or polygamo- 



dioecious. 15. CLEMATIS. 



Sepals with a wide border : flowers perfect. 16. VITICELLA. 



Stamens erect : sepals more or less converging. 17. VIORNA. 



Petals present (in our species), smaller than the sepals. 18. ATRAGENE. 



Leaves alternate, sometimes all basal. 



Sepals spurred. 19. MYOSURUS. 



Sepals spurless. 



A. Leaf-blades entire, toothed, palmately lobed or dissected. 



Petals wanting. 20. TRAUTVETTERIA. 



Petals present. 



a. Blades of the petals with a nectariferous pit at the base. 



Achenes transversely wrinkled : petals white. 21. BATRACHIUM. 



Achenes not transversely wrinkled : petals yellow, at least 

 without. 



