138 MEMOIRS FROM THE DEPARTMENT OF BOTANY OF COLUMBIA UNIVERSITY 
Ivesia tridentata Gray, Proc. Am. Acad. T: 338. 1868. 
Rothrock, in Wheeler’s Exp. 4: 114; Wats. Bot. King’s Exp. 448. 
Horkelia Tilingi Regel, Act. Hort. Pet. 1: 158. 
Potentilla Tiling: Greene, Pittonia, 1: 105. 1887. 
Greene, Fl. Fran. 1: 68. 
InnustRations: Pac. R. R. Rep. 4: pl. 6; Regel, Gart. Fl. 1872, pl. 711.* Pats 
74, f. 1; dissection of flower, f. 2; pistil, f. 3; stamens, f. 4; fruiting hypanthium and 
calyx, 7.10. 
Root deep, perennial, but not very thick. Stems several, ascending or decumbent, 
2-4 dm. high, silky-villous, simple. Stipules very variable, sometimes ovate and entire, 
sometimes finely dissected. Basal leaves numerous, grayish or white-silky, or glabrous 
on the upper surface, pinnate, of 3-4 pairs of cuneate or obovate leaflets, which are gen- 
erally 3-toothed at the apex (rarely 4—5-toothed, or entire) and about 1 cm. in length. 
Stem leaves smaller with 1 or2 pairs. Cyme often somewhat branched with sub-capitate 
small clusters at the end of the branches or the simple stem. Hypanthium silky-villous, 
cupshaped, in fruit 3-4 mm. in diameter; bractlets linear, a third to a half the length of 
the broadly ovate sepals. Petals oblanceolate, a little longer than the sepals. Filaments 
all linear-lanceolate. Pistils 5-10. 
Common throughout the mountain regions of California and southern Oregon. 
21. Horkelia flavescens. 
aed 
IuLusrrations: Puare 75, f. 1-2; dissection of flower, f. 3; pistil, f 4; stamens, 
jf. 6-6; fruiting hypanthium and calyx, f. 7. 
Tufted from a perennial deep root. Stems several, subscapose or with a few small 
leaves, sparingly silly-villous, scarcely more than 1 dm. high. Basal leaves numerous, 
sparingly silky-villous, pinnate, with 8 or 4 pairs of cuneate or obovate leaflets, which are 
about 1 cm. long and 2-3-toothed at the apex. Cyme much contracted, dense, subcapi-- 
tate. Hypanthium silky-villous, cupulate, more or less tinged with brown; bractlets 
linear, about half as long as the ovate-triangular sepals. Petals spatulate, unguiculate, 
yellowish, at least in the dry state. Filaments of the antisepalous stamens triangular 
to lanceolate, those of the antipetalous ones lanceolate. Pistils 8-15. 
This has hitherto been included in H. tridentata, but it is undoubtedly a good species, 
differing in the inflorescence and the flowers, though the vegetative organs are essentially 
the same in the two. 
Califorma: J: G. Lemmon, No. 68, 1894; No. 90, 1875 (type); Miss Pulsifer, 1872; 
Mrs. E. P. Ames, 1872; 1876; Mrs. R. M. Austin, 1887; 1876. 
