532 RANUNCULACEAE 



Eefs.— Myosurus minimus L. Sp. PI. 284 (1753), type European; Jepson, Fl. W. Mid. 

 CaJ. 198 (1901). M. major Greene, Pitt. 3:257 (1898), type loe. Yreka, Greene (recognized 

 by J. C. Nelson, Torreya, 18:194,-1918). Var. .urs Greene, Bull. Cal. Aead. 1:277 (1885), 

 type loe. mesas, San Diego, Orcutt. Var. FiLiroKMis Greene, I.e., type loc. Guadaloujje Isl., 

 Greene. 



3. M. alopecuroides Greene. Leaves 1 line wide, Vo to 214 inches long; 

 spike-like receptacle slender-conical, rather thick, 3 or 6 to 10 lines long, sessile 

 or very sliortly scapose, in clusters of about 4 to 9 ; achenes not flattened on the 

 back, thin-walled and with prominent spreading beak. 



Shallow vernal jiools of alkaline flats: western side of the lower Sacramento 

 and lower San Joaquin valleys. Mar. -Apr. 

 Locs. — Vacaville, Jepson; Antioeh. 



Befs. — Myosurus ALorECUBOlDES Greene, Bull. Cal. Acad. 1:278 (1885), type loe. Antioeh, 

 Curran; Jepson, Fl. W. Mid. Cal. 198 (1901). 



13. RANUNCULUS L. Butteecup. Crowfoot. 



Annual or perennial herbs with divided or entire leaves. Flowers solitary 

 or somewhat corymbed, yellow, or less commonly white, rarely pink. Sepals 5, 

 rarely 4 or 3. Petals 5 (rarely 1 or 3) to 16, with a little nectar-bearing pit 

 at base, the pit commonly covered by a scale. Stamens usually numerous. 

 Achenes numerous, in a globular or oblong cluster. Seed attached near the base 

 of the cell. — Species about 250, all continents. (Latin name for a little frog, 

 some species growing in wet places where frogs are found.) 



Variation Note. — The leaves are always variable in shape or size on a given individual, 

 commonly markedly so. In our species the petals are commonly 5, or varying to 6 or 7, except 

 in E. californicus and R. cauus, which have many petals. E. hebecarpus has only 1 to 3 petals. 



Ecolog. Note. — Our species, for the niost part, grow in the moist vernal beds of winter 

 pools, on the margins of streams or rivulets, or in swamps or wet meadows. A few are am- 

 phibious and float in water but none are characteristic of arid places except E. andersonii, 

 which inhabits sagebrush slopes of the great interior plateau. E. californicus should be men- 

 tioned in this connection. While it grows in a variety of moist and low habitats, where it 

 produces a corresponding number of indefinable leaf forms, the prevailing form abounds on 

 the open slopes of the coast hills. It is a tropophyte, our only species wivich has accommodated 

 itself to the dry naked hills, but its period of development corresponds to the months of the 

 winter and spring rains when the soil is continuously moist. It is, furthermore, not only our 

 most abundant but our most variable species. In drier regions, i.e.. towards the interior, it is 

 less common on the hills and favors low ground ; likewise, in Southern California, it is all bnt 

 confined to cienagas and wet swales. One may also note Ranunculus hebecarpus which is 

 enabled to tolerate the dryness of the soil where it grows by favoring exclusively the shade of 

 oak or other trees in open woods of the drier foothills. 



A. Nectar-bearing pit on petal claws covered with a scale. 



1. Achenes icith a firm dose coat, not loose or iitrie-ular. — Subgenus EimANUNCULUS. 



Aquatic ; perennials. 



Leaves iinely dissected 1. H. delphinifoUus. 



Leaves cordate, entire 2. E. hydrocharoides. 



Terrestrial plants, often in muddy or marshy places, but not truly aquatic or floating. 

 Achenes not spiny-nuirieate, nor with hooked hairs. 

 Leaves simple, entire; achenes thickish. 



Perennials ; petals 5, mediimi to showy ; achenes not papillate. 



Stems erect or ascending from a cluster of fibrous roots, not rooting at the nodes. 

 Leaves glabrous or slightl.y hairy; .stems mostly leafy; achenes turgid, glabrous 



3. B. alismaefoJius. 

 Leaves mostly densely pilose; stems naked or nearly so; achenes turgid, 



pubescent 4. H. lemmonii. 



Stems filiform, creeping or decumbent, rooting at the nodes 5. E. fiamm^da. 



Annuals; basal leaves ovate; petals 1 to 3, minute; achenes papillate ..6. E. piLsillus. 



