394 RANUNCULACEAE (CKOWFOOT FAMILY) 



1. RANUNCULUS [Toum.] L. Crowfoot. Buttercup. 



Annuals or perennials ; stem-leaves alternate. Flowers solitary or somewhat 

 corymbed, yellow, rarely white. (Sepals and petals rarely only 8, the latter often 

 more than o. Stamens occasionally few.) — (A Latin name for a little frog; 

 applied by Pliny to these plants, the aquatic species growing where frogs abound. ) 



§L FICARIA Boiss. Boots tuberous-thickened; sepals 3; petals about 8, 

 yellovj, with a free scale over the honey ylancl. 



1. R. FicXria L. (Lesser Celandine.) Glabrous and somewhat succu- 

 lent ; leaves basal on long stoutish petioles, ovate, rounded, deeply cordate, sub- 

 ore n ate ; flowers scapose, 2 cm. in diameter. (Ficaria Karst.) — Wet places, 

 occasional ; Mass. to D. C. Ap)r., May. (Introd. from Eurasia.) 



§2. BATRACHIUM DC. Petals with a spot or naked pit at base., ichite, oi 

 only the daw yellow; achenes maryinless, transversely icrinkled ; aquatic 

 or suhaquatic perennials., with the immersed foliage repeatedly dissected 

 (mostly by threes) into capillary divisions ; peduncles l-Jlowered, opposite 

 the leaves. 



* Beceptacle hairy. 



2. R. circinatus Sibth. (Stiff Water C.) Leaves all under water and 

 sessile, with broad conspicuous stipules, the divisions and subdivisions short, 

 spreading in one roundish jjlane, rigid, not collapsing v;hen withdrawn from the 

 water. {B. divaricatus auth., not Schrank ace. to Hiern.) — Ponds and slow 

 streams, Vt. to Pa., la., northw. and westw., rather rare. (Eu.) 



;]. R. aquatilis L., var. capillaceus DC. (Common White Water C.) 

 Leaves all under water and mostly petioled, their capillary divisions and sub- 

 divisions rather long and soft., usually collapsing more or less ichen withdrawn 

 from the water ; petiole rather narrowly dilated. {B. aquatilis, var. trichophyl- 

 lus Gray ; Batrachium trichophyllum Bosch ; B. flaccidum Rupr. ; B. Droueiii 

 Nym. ; and B. confervoides auth., not Fries.) — Common, especially in slow- 

 flowing waters, the eastern form with more soft and flaccid leaves. June- 

 Aug. (Eu.) Var. caespitosus DC. A dwarf terrestrial variety or possibly 

 mere state, rooting at the nodes, the small leaves somewhat fleshy, with broader 

 rigid divisions. — S. 111. (Schneck), and westw. (Eu.) 



* * Beceptacle glabrous ; no submersed leaves. 



4. R. hederaceus L. Rooting freely in shallow water ; leaves all reniform, 

 angulate-lobed. (Batrachium S. F. Gray.) — Fresh-water marshes, Nfd. ; 

 s. Md. ; s. e. Va. (Nat. from Eu.) 



§ 3. HAL6dES Gray. Petals yellow, with nectariferous pit and scale; carpels 

 thin-walled, striate, in a subcylindric head; scapose, spreading by runners. 



5. R. Cymbalaria Pursh. (Sea-side C.) Glabrous; scapes 4-22 cm. high, 

 1-7 -flowered ; leaves clustered at the root and on the joints of the long rooting 

 runners, roundish-heart-shaped or kidney-shaped, crenate, rather fleshy, loivg- 

 petioled ; petals 5-8. (Oxygraphis Prantl.) — Lab. to N. J., also along the Great 

 Lakes and in alkaline soil of the interior. June-Aug. (Greenl., Eurasia.) 



Var. alpinus Hook. Dwarf ; leaves 3-toothed, only 3-6 mm. broad. — Cape 

 Breton L, N. S., e. Que., and northw. 



§ 4. P^URANtlNCULUS Gray. Petals with a little scale at the base., yellow; 



achenes nerveless. 



* Achenes smooth, or nearly so ; mostly perennial. 



•«- Aquatic; immersed leaves Jiliformly dissected; as in § Batrachium. 



6. R. delphinifblius Torr. (Yellow Water C.) Stems floating or im- 

 mersed, with the Univcs all repeatedly .S-furked into loim filiform divisions, or 

 sometimes cn-eiiing in tiie mud (jjerennial by rooting from the nodes, if at all) ; 

 petals 5-8, deep bright yellow, 8-12 mm. long, much larger than the sepal.-^ : 



