BUTTERCUP FAMILY. 169 



A. occidentalis W;its. Stems from the crown of a thick vertical root, 1- 

 flowered; leaves much divided; achene with long plumose tails. — High Sierra 

 Nevada. 



8. MYOSURUS L. 



Dwarf annuals with entire tufted radical leaves and naked 1 -flowered scapes. 

 Sepals 5, spurred at base. Petals 5, with a nectar-bearing hollow at the summit 

 of the slender claw. Stamens 5 to 20. Achenes numerous, crowded on a long 

 and slender spike-like receptacle. Ovules attached near the summit of the cell. 

 (Greek mus, a mouse, and oura, a tail, in allusion to the curious receptacles.) 



Flowers on scapes; achenes with an appressed beak 1. M. minimus. 



Flowers sessile, the spike-like receptacles in a close cluster; achenes with a spreading 

 beak 2. M. alopccuroides. 



1. M. minimus L. Mouse Tail. Leaves linear-filiform; scapes 3 to 6 

 in. high, the slender receptacles % to 1%, commonly about 1 in. long; mature 

 achenes with somewhat rhomboidal back and very low keel ending in a straight 

 appressed or rarely obsolete tip. 



Low ground: inner Coast Ranges; Sacramento and San Joaquin valleys; 

 far eastward. 



2. M. alopecuroides Greene. Antioch Mouse Tail. Leaves 1 line wide, 

 2 1 -. in. long or less; spike-like receptacles 6 to 10 lines long, rather thick, 

 sessile, in clusters of about 4 to 9; achenes with prominent spreading beak. 



Shallow vernal pools : Antioch, Stockton and north to Vacaville. Mar.-Apr. 

 Too near M. sessilis Wats. 



9. RANUNCULUS L. Buttercup. 

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

 or somewhat corymbed, yellow or white. Sepals 5, rarely 4 or 3. Petals 5 

 (rarely 1 or 3) to many, with a little nectar-bearing pit at base, the pit com- 

 monly covered by a scale. Stamens usually numerous. Achenes numerous, 

 in a globular or oblong cluster. Ovules attached near the base of the cell. 

 (Latin name for a little frog, some species aquatic, growing where frogs are 

 found.) 



A. Petals yellow; nectar-bearing pit covered by a scale. 



Leaves undivided; achenes not strongly flattened. 



Petals 5; beak of achene straight but short; perennial 1. R. Hammula.. 



Petals 1 to 3, minute; achene .beakless or nearly so; annual 2. R. pnsillus. 



Leaves lobed, cleft or divided; achenes flattened. 

 Perennial; achenes smooth (hispidulous in no. 7). 



Leaves with mostly 3 leaflets; petals 5, emarginate; beak subulate, straight 



3. R. bloomcri. 

 Leaves ternately once or twice divided, the divisions parted, laciniate or lobed. 



Petals 5 to 8; beak subulate, as long as body of achene 4. R. orthorhyncus. 



Petals 5; beak very broad, only slightly curved 5. R. canus. 



Petals many (about 9 to 16), in some of the varieties few (5 to 8); beak very 



short, recurved; herbage more or less pubescent or hirsute; common 



6. R. californicus. 



Petals 5; beak rather slender, curved or hooked 7. R. occidentalis. 



Annual. 



Achenes with hooked hairs; slender herbs with minute flowers 8. R. hebecarpus. 



Achenes bearing prickles on the sides, the margin with raised border; flowers 4 or 



5 lines broad 9. R. muricatus. 



B. Petals white; nectar-bearing pit not covered by a scale; aquatic. 



Leaves submersed, dissected into capillary divisions; achenes many 10. R. aquatilis. 



Leaves floating, with broad divisions ; submersed leaves as in the preceding or none; 

 achenes 4 to 6 11. R. lobbii. 



1. R. flammula L. var. intermedius Hook. Spearwort. Perennial; 



