138 MEMOIRS FROM THE DEPARTMENT OF BOT OF COLUMBIA UNIVERSITY 



Ivesia tridentafa Gray, Proc. Am. Acad. 7: 338. 1868. 



Rothrock, in Wheeler's Exp. 4 : 114 ; Wats. Bot. King's Exp. 448. 



Horkelia Tilingi Kegel, Act. Hort. Pet. 1: 153. 



Potentilla Tilingi Greene, Pittonia, 1: 105. 1887. 



Greene, Fl. Fran. 1: 68. 



Illustrations: Pac. K R. Rep. A: pi. 6; Regel, Gart. Fl. 1812, pi. 711.* Plate 

 7 4 J. 1 ; dissection of flower, /. 2 ; pistil, /. 3 ; stamens, /. A ; fruiting hypanthium and 

 calyx,/. 5. 



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 or 2 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 Cahfornia and southern Oregon. 



21. Horkelia flavescens. 



Illustrations: Plate 75, f. 1-2; dissection of flower,/. 3; pistil, /. A I stamens, 

 /. 5-6; fruiting hypanthium and calyx, /. 7 . 



Tufted from a perennial deep root. Stems several, subscapose or with a few small 

 leaves, sparingly silky-villous, scarcely more than 1 dm. high. Basal leaves numerous, 

 sparingly silky-villous, pinnate, with 3 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 B.. tridentata, but it is undoubtedly a good species, 

 diflfering in the inflorescence and the flowers, though the vegetative organs are essentially 

 the same in the two. 



California: 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. 



