154 University of California Puhlications in Botany [Vol.9 



17. BETULACEAE (Birch Family) 



Pistillate catkins clustered, becoming pendulous oval woody cones, their per- 

 sistant scales 5-lobed at the apex; stamens 1-7 1. Alnus 



Pistillate catkins solitary, the ultimately deciduous scales 3-lobed at the apex; 

 stamens 2 2. Betula 



1. ALNUS 



1. Alnus tenuifolia Nutt., Sylva, vol. 1, p. 32. 1842. 



A. incana var. virescens Wats., Bot. Calif., vol. 2, p. 81. 1880. 

 A. occidentalis Dippel, Handb. Laubh., vol. 2, p. 158. 1892. 



Type locality. — "On the borders of small streams within the 

 Range of the Rocky Mountains, and afterwards in the valleys of the 

 Blue Mountains of Oregon." 



Range. — British Columbia and Mackenzie south to California and 

 New Mexico. 



Zone. — Transition and Canadian. 



Specimens examined. — Near Donner Lake, Heller 6952 ; Lake 

 Tahoe, Dudley, August 23, 1909; Glen Alpine, W. W. Price, July, 

 1898; Grass Lake, Tahoe, 7,200 feet, McGregor; Carson Spur, Alpine 

 County, 8,500 feet, Hansen 809; shores of Suzy Lake, Tahoe, 7,800 

 feet. Smiley 174 ; Angora Lake, Tahoe, 8,000 feet. Smiley 35 ; Chiquito 

 Creek, Sierra National Forest, 6,000 feet, Abrams 4931; Upper San 

 Joaquin, Congdon, August 19, 1895. 



Miss Eastwood®^ found this in the Sierra of Tulare County along 

 Bubbs Creek and Kings River. 



2. BETULA 



1. Betula glandulosa Michx., Fl. Bor. Am., vol. 2, p. 180. 1803. 



Type locality. — "Circa lacus, a sinu Hudsonia ad Mistassins. " 



Range. — Subarctic America south to the northern Sierra Nevada, 

 in the Rockies to New Mexico, and in the eastern United States to 

 Minnesota, Great Lakes, and New England. 



Zone. — Canadian. 



Specimens examined. — Big Meadows, Plumas County, Lemmon, 

 May, 1879 ; Plumas County, Mrs. Austin in 1878. 



No other collections of the Scrub Birch are known from the Sierra 

 though it has been often collected in the Mt. Lassen region and further 

 north in the Warner Mountains of Modoc County ; it is barely possible 

 that these specimens were in fact collected farther north than the 

 data on the labels indicate. 



