CATALOGUE. 1 ] 3 



Potentilla Plattensis, Nutt. — Sparingly covered throughout with 

 an appressed silky pubescence, low, 4-8' long, branching from the root; 

 leaves 2-4' long, pinnate, with 11—13 leaflets, each of which is cuneate in 

 outline, and deeply cleft into 5-7 linear lobes; flowers in an open cyme, 

 on long - , slender pedicels, less than £' in diameter, bright yellow ; bractlets 

 half shorter than the calyx -lobes; carpels rather indefinite, but about 30; 

 styles filiform and terminal. — Twin Lakes, Colorado (346, 377). 



Potentilla geacilis, Dougl. — Colorado (368, 372) ; Utah. 



Var. rigida, Watson. — A larger and more villose form, with loose 

 inflorescence, and larger, more veiny leaves. Same variety also from Utah. 



Potentilla dissecta, Pursh. — Low, alpine, villose, with soft, spreading 

 hairs, or glabrous, usually decumbent, 3-10' long - ; leaflets 3-7, pinnate or 

 digitate, glaucous, cuneate-oblong, serrate or even pinnately cleft, with the 

 divisions tipped with long, whitish hairs; receptacle very villous; style 

 filiform, terminal. — Colorado (371, 378). 



Potentilla humifusa, Nutt. — Spreading, herbaceous, perennial; leaves 

 densely white tomentose on the under surface, greener and villose on the 

 upper surface; leaflets 3-5, cuneate-oblong, with 3-5 rounded teeth at the 

 apex of each leaflet; stems few-flowered, 3-4' long; calyx-lobes larger than 

 the bractlets; both calyx and bractlets densely villose; petals 2" long; 

 styles terminal, filiform. — Colorado (365). 



Potentilla nivea, L. — Colorado (366). 



Potentilla Thurbeei, Gray (PI. Nov. Thurb. p. 318). — Herbaceous, 

 perennial, 1-2° high, ascending, loosely villose, with long, spreading hairs; 

 leaves digitate, upper sessile or nearly so, lower petioled, commonly 5-, 

 sometimes 7-foliolate; leaflets obovately-cuneiform, regularly, deeply, and 

 sharply serrate, lower surface canescent and villose gray or white, upper 

 puberulent and green (smoother when old) ; stipules lanceolate or ovate, 

 united to the petiole for one-fourth their length; bractlets lanceolate, acute, 

 about as long as the sepals, though somewhat narrower, more or less 

 villose; petals deep purple, broadly obcordate, about as long as the sepals; 

 style terminal; carpels glabrous; disk thickened somewhat, 5-angled, with 

 an inner circle of 5 stamens, with rather fleshy filaments inserted (one) 

 on each angle; outer stamens with more filiform filaments; receptacle 



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