ROSE FAMILY 



425 



8. Ivesia sericoleuca Rydb. Plumas Ivesia. Fig. 2405. 



Horkelia sericoleuca Rydb. Mem. Dept. Bot. Columbia Univ. 2: 144. pi. 85. 1898. 

 Ivesia sericoleuca Rydb. N. Amer. Fl. 22: 284. 1908. 



Stems decumbent or ascending, 15-40 cm. high; caudex woody, covered with densely hirsute 

 old leaf-bases ; plant more or less densely white-sericeous to tomentose. Basal leaves 10-25 cm. 

 long; leaflets crowded or imbricate, 5-15 mm. long, divided to the base into 2-4 oblong to elliptic 

 lobes; cymes dense, many-flowered, or when open the flowers clustered in glomerules; hypan- 

 thium campanulate, 2-2.5 mm. deep, glabrous within; bractlets narrowly lanceolate, about half 

 as long as sepals; sepals lanceolate, acuminate, 3.5-5.5 mm. long; petals exceeding sepals; 

 stamens 20, filaments filiform; pistils 4-7; achenes smooth, pyriform. 



Dry flats and slopes, Arid Transition Zone; eastern slopes of the Sierra Nevada, Plumas County to Nevada 

 County, California. Type locality: Sierra County, California. June-Sept. 



9. Ivesia Kingii S. Wats. King's or Alkali Ivesia. Fig. 2406. 



Ivesia Kingii S. Wats. Bot. King Expl. 91, 448. 1871. 



Potentilla Kingii Greene, Pittonia 1 : 105. 1887. 



Horkelia Kingii Rydb. Mem. Dept. Bot. Columbia Univ. 2: 148. 1898. 



Stems several from thick perennial root, decumbent or ascending, 15-30 cm. high, nearly or 

 quite glabrous. Basal leaves 6-10 cm. long; leaflets crowded, 3-parted, the segments oblong to 

 rounded, entire, 2-6 mm. long, glabrous and glaucous or rarely ciliate on the margins ; upper 

 cauline leaves with simple leaflets ; cymes in a loose panicle ; hypanthium sparsely pubescent 

 without, glabrous within, bractlets subulate; petals white, exceeding the sepals, clawed, the 

 blades orbicular; stamens 15-20; pistils 2-8. 



Alkaline soils, Upper Sonoran and Arid Transition Zones; western Nevada and Mono County, California, 

 to western Utah. Type locality: "Monitor, Diamond and Ruby Valleys, Nevada; 6,000 feet altitude." July- Aug. 



2402. Ivesia campestris 



2403. Ivesia unguiculata 



2404. Ivesia Pickeringii 



2405. Ivesia sericoleuca 



2406. Ivesia Kingii 



2407. Ivesia pygmaea 



