424 



ROSACEAE 



6. Ivesia unguiculata A. Gray. Yosemite Ivesia. Fig. 2403. 



Ivesia unguiculata A. Gray, Proc. Amer. Acad. 7: 339. 1868. 

 Potentilla unguiculata Hook. f. Bot. Mag. 37: pi. 6560. 1881. 

 Potentilla ciliata Greene, Pittonia 1: 103. 1887. 

 Horkelia unguiculata Rydb. Mem. Dept. Bot. Columbia Univ. 2 : 



146. 1898. 



Stems several, decumbent or ascending, 3-4 dm. high, simple, sparingly silky-villous. Basal 

 leaves numerous, canescent, but not densely silky with long hairs; leaflets numerous, crowded, 

 5-7 mm. long, divided to the base into linear-oblong lobes ; cyme subcapitate ; hypanthium 4 mm. 

 broad, slightly silky ; sepals 2-3 mm. long, broadly lanceolate ; petals white, broadly spatulate or 

 obovate; stamens 10-15. 



Borders of mountain meadows, Arid Transition Zone; Sierra Nevada, Mariposa County to Fresno County, 

 California. Type locality: Westf all's Meadow, Yosemite Valley, California. June- Aug. 



7. Ivesia Pickeringii Torr. Pickering's Ivesia. Fig. 2404. 



Ivesia Pickeringii Torr. ex A. Gray, Proc. Amer. Acad. 6: 531. 1865. [Bot. Wilkes Exp. 288. pi. 4. 1874.] 



Potentilla Pickeringii Greene, Pittonia 1 : 105. 1887. 



Horkelia Pickeringii Rydb. Mem. Dept. Bot. Columbia Univ. 2: 145. 1898. 



Stems ascending, leafy, 25-45 cm. long ; caudex stout, woody, covered with glabrous old leaf- 

 bases, plant densely and finely villous, minutely viscid. Basal leaves 8-18 cm. long; leaflets 

 crowded or imbricate, 2-5 mm. long, parted to the base, the lobes oblong to obovate; cyme 

 corymbosely branched, the flowers scattered or in subcapitate glomerules ; hypanthium campanu- 

 late, 2-2.5 mm. deep, pilose within; bractlets lanceolate, 4-5 mm. long; petals broadly spatulate, 

 slightly exceeding the sepals; filaments filiform; pistils 2, rarely 3; achenes ellipsoid, narrowed 

 to a blunt apical beak, often similarly beaked at the base. 



Mountain slopes, Arid Transition Zone; Siskiyou and Trinity Counties, California. Type locality: on the 

 Klamath River, according to Torrey, probably on the Sacramento according to Gray. July-Sept. 



2399 



2396. Horkelia tridentata 



2397. Horkelia purpurascens 



2398. Ivesia santolinoides 



2399. Ivesia callida 



2400. Ivesia Jaegeri 



2401. Ivesia argyrocoma 



