1921] Smiley: Flora of the Sierra Nevada of California 231 



5. HOLODISCUS 



Leaves ovate; pubescence, if present, sericeous 1. H. dumosus 



Leaves round-ovate; pubescence of spreading, somewhat rigid hairs 



2. H. Boursieri 



1. Holodiscus dumosus Heller, Cat. N. Am. PL, p. 4. 1898. 



Spiraea dumosa jSTutt., in T. and G., Fl., vol. 1, p. 416. 1840, as synonym; 



Hook., Lond. Joum. Bot., vol. 6, p. 217. 1847. 

 Spiraea discolor var. duviosa Wats., Bot. Calif., vol. 1, p. 170. 1878. 

 Sericotheca concolor Eydb., N. Am. Fl., vol. 22, p. 264. 1908. 

 HolodiscTis saxioola Heller, Muhl., vol. 1, p. 41. 1904. 

 Sericotheca ohovata Eydb., N. Am. Fl., vol. 22, p. 264. 1908. 



Type locality. — East slope of the Rocky Mountains along Platte 

 River. 



Range. — Wj'oming to Chihuahua and west to the Pacific Coast. 



Zone. — Canadian to Hudsonian. 



Specimens examined. — Granite rocks at Donner Pass, 7,000 feet, 

 Heller 7160; summit back of Jonesville, Butte County, 7,000 feet, 

 Heller 11667 ; Silver Lake, Amador County, 7,200 feet, E. Mulliken 

 148 ; Mt. Tallac, Tahoe, talus slope on east side, 8,300 feet, Smiley 226 ; 

 Hunter Creek Canon, Washoe County, Nevada, 7,500 feet, Heller 

 10353 ; Glen Alpine, Tahoe, 7,000 feet, W. W. Price, July 12, 1898 ; 

 Clear Creek Caiion, Ormsby County, Nevada, 2,000-2,615 m., Baker 

 1431; Mono Pass, Congdon, August 16, 1894; Cloud's Rest trail, 7,400 

 feet, Smiley 496 ; summit of Half-dome, Yosemite, Lemmon, August 

 19, 1878 ; trail from Round meadow to Nellie Lake, Fresno County, 

 8,100 feet. Smiley 592; Coyote Creek, Tulare County, Culbertson 

 (B4332) ; Mt. Silliman, Tulare County, 9-10,000 feet, Dudley 1470; 

 White-water Peak, Tulare County, among summit rocks, Dudley 632 ; 

 mountains near Farewell Gap, 10-11,000 feet, Purpus 5121. 



Although as Dr. H. M. Hall has pointed out^^ the vegetative char- 

 acters of this shrub change with change of environment, the essential 

 specific characters of the flowers remain constant ; the same is true of 

 the nature of the pubescence, which is alwaj's more or less silky and 

 present in varying amounts. 



2. Holodiscus Boursieri (Carr.) Rehder., Cycl. Hort., vol. 3, p. 



1498. 1915. 



Spiraea Boursieri Carr., Rev. Hort., 1859, p. 520. 1859. 

 Sericotheca Boiirsieri Rydb., N. Am. Fl., voL 22, p. 263. 1908. 



Type locality. — "California," without locality. 



Range. — Sierra Nevada. 



Zone. — Canadian and Hudsonian. 



