202 RANUNC'ULACEyH. 



10. R. aquatilis L. Water Buttercup. Perennial; leaves 

 submersed, all many times dissected into filiform or capillary divi- 

 sions; flowers I in. in diameter or less; sepals deciduous; styles 

 subulate, rarely persisting; achenes transversely rugose, commonly 

 hispidulous, about 11 to 18 in a rather compact round head. 



Common in ditches and ponds, less frequently in running water; 

 in the Coast Ranges and Sierras. Pilarcitos Lake, San Mateo Co.; 

 Berkeley; Sonoma; Upper Napa Valley. In the last locality floating 

 leaves are found, 7 to 10 lines broad, all of the oval or orbicular 

 segments 2, 3, or 4-notched. 



11. R. Lobbli Gray. Lobb's Buttercup. Annual; submersed 

 leaves none, or when present, few and as in the preceding; floating 

 leaves 6 lines broad, divergently 3-parted into oblong or ovate lobes, 

 the middle one commonly entire, the lateral notched; stamens 5 to 10; 

 petals withering persistent; styles filiform, about 3 times the length 

 of the ovary; achenes few (4 to 6), rather sharply rugose, the mature 

 ones sometimes with minute black dots. 



Whitening the surface of shallow vernal ponds, Marin Co. to 

 Upper Napa Valley. Apr. -May. 



9. THALICTRUM L. Meadow Rue. 



Perennial herbs with tall erect stems from a short rootstock 

 bearing hi- or tri-ternately compound leaves with petiolulate (or 

 some sessile) leaflets. Plowers many, small, panicled, in ours dioe- 

 cious. Sepals in pistillate flowers 4 to 7, in staminate flowers more 

 commonly 4, greenish or more or less petal-like. Petals none. 

 Stamens numerous with long mucronate anthers on capillary fila- 

 ments. Achenes 4 to 15, veined or furrowed and usually acute at 

 both ends, sometimes inflated, tipped with the persistent long styles. 

 (Prom the Greek thallo, bloom, the application uncertain.) 



1. T. polycarpum Wats. Glabrous, aromatic, IJ to 3 ft. high; 

 leaflets ovate to roundish, J to 1 in. long, the pair below the terminal 

 one usually sessile, serrate or incised or divided into 2 or 3 segments, 

 the teeth acute or acutish, rather prominently veined beneath; pan- 

 icle 3 to 6 in. long, terminal or with accessory branches from the 

 upper axils; sepals elliptic to ovate, mostly acute; stamens 16 to 2-i, 

 anthers yellowish; pistils of about the same number, styles purplish; 

 achenes somewhat inflated, the sides marked with anastomosing 

 veins. 



Coast Ranges: Conn Valley, Napa River Basin; Marin Co. Last 

 of Mar.-May. In the Contra Costa Hills passing into the var. 

 hbsperium (T. hesperium Greene); leaflets with more obtuse lobes, less 

 veiny beneath, often glandular, puberulent, as also the inflorescence. 

 — Berkeley and Oakland Hills. Apr.-May. 



10. ACT/CA L. Baneberry. 

 Perennial herbs with bi- or tri-ternately compound ample leaves. 

 Flowers small, white, in a short terminal raceme. Sepals about 4, 

 roundish or obovate, concave, caducous. Petals small, plane, entire. 



