1. Potentilla Thurberi Gray. 



Perennial with a woody taproot and short caudex; stem ascending, 3-7 dm. tall, 

 finely pubescent and sparingly villous; basal and lower stem leaves long-petioled, 

 digitately 5- or 7-foliolate, glabrate to slightly sericeous (var. Thurberi) to densely 

 silvery-sericeous [var. atroruhens (Rydb.) Kearn. & Peeb. (P. atrorubens Rydb.)] 

 beneath; leaflets obovate, 3-5 cm. long, coarsely toothed with broad teeth or 

 almost crenate; upper stem leaves sessile, 3- or 5-foliolate, with oblong leaflets; 

 stipules 1-2 cm. long, broadly ovate, coarsely toothed; cyme open and branched; 

 flowers about 1.5 cm. across; hypanthium puberulent, in fruit about 1 cm. in 

 diameter; bractlets lanceolate, 5-6 mm. long, about equal to the triangular acute 

 sepals; jjetals almost orbicular, emarginate, exceeding the sepals, dark-reddish- 

 purple, 7-10 mm. long; stamens 20 to 30, the inner 5 with thicker filaments, 

 borne on a ringlike thickening of the disk; pistils numerous. 



In wet meadows, seepage along streams and about water bodies, and wooded 

 slopes, in N. M. (Grant, Lincoln, Otero, Sierra and Socorro cos.) and Ariz. 

 (Apache to Coconino and s. to Cochise and Pima cos.), June-Sept.; also n. 

 Mex. 



2. Potentilla fniticosa L. Shrubby or bush cinquefoil. 



Much-branched shrub, with very leafy erect or ascending stems, 2-12 dm. high, 

 the reddish-brown bark shreddy; leaflets 3 to 7, linear to oblong, entire, acute 

 at each end, 5-20 mm. long, silky-pubescent, the margins revolute; flowers in 

 small loose cymes or solitary; bractlets linear-oblong, usually a little longer than 

 the ovate acuminate sepals; petals yellow, orbicular, 5-15 mm. long. 



Wet (sometimes saline) meadows, creek bottoms, along streams and on moist 

 rocky slopes, in N. M. (Rio Arriba, Bernalillo, Otero and Sandoval cos.) and 

 Ariz. (Apache and Coconino cos.), June-Sept.; widely distributed in cooler parts 

 of the N. Hemis. 



This handsome-flowered shrub does well under cultivation, and various forms 

 have been selected for horticultural use. In nature, plants are heavily browsed 

 by deer and domestic stock. 



3. Potentilla norvegica L. Fig. 492A. 



Stout leafy annual or short-lived perennial, to 9 dm. high; stem erect or 

 ascending, much-branched, hirsute with stiff mostly spreading hairs, often with 

 shorter pubescence intermixed; lower leaves long-petioled, 3-foliolate; leaflets 

 obovate to oblanceolate, to 8 cm. long, coarsely serrate, usually more or less 

 hirsute, otherwise green; upper leaves sessile, often with narrow leaflets; in- 

 florescence a leafy cyme; calyx in fruit enlarging to 17 mm. high, its bracteoles 

 acutish; petals yellow, obovate, mostly shorter than calyx lobes; stamens 15 to 

 20; style slenderly conical at base, subterminal, about equaling the mature carpel; 

 achenes longitudinally ribbed, to 1.3 mm. long. Incl. var. hirsuta (Michx.) Lehm., 

 P. monspeliensis L. 



In wet meadows and in marshes about lakes and ponds, along irrigation ditches 

 and in thickets, in n.e. Okla. (Delaware Co.), Trans-Pecos Tex., N. M. (Rio Arriba, 

 San Juan, San Miguel, Taos and Union cos.) and Ariz. (Apache, Coconino and 

 Greenlee cos.), May-Sept.; widespread in N.A.; Euras. 



4. PotentiJla pentandra Engelm. Fig. 493. 



Slender annual or biennial, ascending to about 1 m. tall; stems rather stout, 

 leafy, hirsute, chiefly branching and flowering above the middle; lower leaves 

 pedately 5-foliolate or 3-foliolate with the lateral leaflets 2-cleft, with hirsute 

 petioles 3-8 cm. long; uppermost leaves 3-foliolate and very short-petioled; leaflets 

 2-10 cm. long, oblong to oblanceolate or cuneate, deeply serrate, pubescent on 



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