32 MEMOIRS FROM THE DEPARTMENT OF BOTANY OF COLUMBIA UNIVERSITY 
Leaves white-tomentose, especially beneath. 
Leaves silky as wellas tomentose ; bractlets nearly equalling the acute sepals; 
branches erect. 99. P. Hippiana. 
Leayes tomentose on both sides; bractlets shorter than the acuminate sepals; 
branches spreading. 
Stem ascending, not very slender. 100. P. effusa. 
Stem erect, very slender ; pistils few. 101. P. Coloradensis. 
Leaves more or less white-wooly on both sides. 102. P. Brewer. 
Leaves grayish silky. 
Stem stout, erect, 6-7 dm. high ; leaflets obovate, oblong, coarsely serrate. 103. P. ambigens. 
Stem 1-4 dm. high, leaflets cuneate or linear-oblong, toothed at the apex only. 
Stem ascending or decumbent ; leaves conduplicate ; pistils numerous. 104, P. erinita. 
Stem erect; leaves flat; pistils 5-12. 105. P. Lemmon. 
§ 21. CANDICANTES. 
Consists of only one Mexican species, in many respects resembling the Multijugae, 
but with densely silvery-white pubescence. 
A single species. 106. P. candicans. 
§ 1. HAEMATOCHRI. 
1. Potentilla Thurberi Gray. 
Potentilla Thurberi Gray, Mem. Am. Nead (UL) 5 23185) 18547 
Lehm. Ind. Sem. Hort. Hamb. 1854: 10; Otto’s Gartenz. 10: 459, Rev. Pot. 92; 
Torr. Bot. Mex. Bound. Surv. 64; Wats. Proce. Am. Acad. 8: 561; Rothrock, in U. 5. 
Geog. Surv. 4: 118 (partly ); Rydberg, Bull. Torr. Bot. Club, 24:11. 
IntustRATIonNs: Pare 2, f. 1; staminiferous disk, f. 2; pistil, f. 3; stamens, fae 
and 5; fruiting hypanthium and calyx, f. 6. 
Stem ascending, 3-7 dm. high, finely pubescent and sometimes somewhat villous. 
Stipules large, 1-2 em. long, broadly ovate, coarsely toothed. Basal and lower stem 
leaves long-petioled, digitately 5-7-foliolate, glabrate or slightly silky, thin, sometimes 
slightly paler beneath but not tomentose. Leaflets obovate, 3-5 cm. long, coarsely 
toothed with broad teeth, almost crenate. Upper stem leaves sessile, 3—5-foliolate with 
oblong leaflets; eyme open and branched. Flowers about 15 mm. in diameter. Hypan- 
thium puberulent, in fruit about 1 em. in diameter. Bractlets lanceolate, about equal- 
ling the triangular acute sepals. Petals nearly orbicular, emarginate, exceeding the 
sepals, dark reddish purple. Stamens 20, the inner 5 with thicker filaments and 
borne on a ring-like thickening of the disk. Pistils numerous. 
