Further Studies on the Potentilleae 



By P. A. Rydberg 



I. WEST AMERICAN SPECIES 



fc Potentilla horrida sp. nov, 



A stout perennial with very thick woody root and a short cau- 

 dex covered with the thick coriacious brown remains of old 

 leaves: stems ascending, 1.5-4 dm. high, stout, few-leaved, hir- 

 sute-villous : petioles of the basal leaves 5-10 cm. long, stout, 

 densely hirsute -villous, broadened at the base and surrounding the 

 stem : leaves digitate; leaflets usually 5, linear-oblong or oblong- 

 lanceolate, obtuse, crenulate, 3-5 cm. long, 7-1 2 mm. wide, densely 

 pubescent on both sides, almost velvety : pubescence at first white, 

 later on brown, consisting of tomentum and longer silky hairs: stem- 

 leaves similar or trifoliolate, much smaller ; the upper subsessile ; 

 the stipulates lanceolate to linear-subulate, 1-3 cm. long, adnate to 

 the petioles 2 cyme rather congested : hypanthium and calyx 

 densely pilose : bractlets lanceolate, acute, about half as long as 

 the ovate-lanceolate sepals which are about 5 mm. long : petals 

 yellow, broadly obovate, about 7 mm. long. 



A species of the gracilis group, but resembling most P. Haema- 

 tochrus in habit and pubescence. It differs, however in the coarser 

 pubescence, the 5-foliolate, instead of 7-foliolate leaves and the 

 yellow petals. The type specimens were found at an altitude of 

 2250 m. 



Mexico, State of Chihuahua : Sierra Madre, near Colonia 

 Garcia, 1 800, Townsend & Barber, 16. 



Potentilla brunnescens sp. nov. 



A tall strict perennial with short scaly rootstock : stem 4-5 

 dm. high, pubescence, especially above, tinged with brown or pur- 

 plish : basal leaves digitately 5-7-foliolate ; petioles often 2 dm. 

 long, villous with spreading hairs ; leaflets 4-7 cm. long, broadly 

 oblanceolate in outline, brownish strigose on both sides, paler be- 

 neath, pectinately divided to near the midrib ; segments linear, ob- 

 tuse : stem-leaves similar but short-petioled or subsessile, smaller : 

 c yme many-flowered, corymbiform : hypanthium and calyx vil- 

 lous-strigose : bractlets linear, obtuse, about half as long as the 



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