(342 ) 
BETULACEAE. Bircu Famity. 
1. ALNUS. ALpeEr. 
1. AtNus RHOMBIFOLIA Nutt. N. Am. Sylva 1: 33. 1842. 
. Type locality: “In the vicinity of Monterey, in Upper Cali- 
fornia.” 
Distribution: Idaho and eastern Washington south through 
the Sierra Nevada and the Coast Ranges to San Diego. In 
southern California the alder is most frequent along streams in 
the mountains from 400-1000 meters. On the coastal slope it 
sometimes extends along the streams well into the valleys, espe- 
cially in the vicinity of Pasadena. On the desert slopes it extends 
down the principal streams to the juniper belt. Transition and 
Upper Sonoran. 
Specimens examined: Sulphur Mountain Spring, near Santa 
Paula, Abrams &§ McGregor 59; Red Reef Canyon, Topatopa 
Mountains, Abrams tf McGregor 126; Rock Creek, desert slope 
of the San Gabriel Mountains, Abrams &§ McGregor 527; Arroyo 
Seco, near Pasadena, Grant 36. 
FAGACEAE. Beecu Famity. 
Involucre 1-flowered; fruit an acorn. 
Staminate aments densely flowered, erect; cup of acorn conspicuously 
echinate. 1. Pasania. 
Staminate aments loosely flowered, drooping; cup of acorn scaly (in 
ours), not echinate. 2. Quercus. 
Involucre 1-3-flowered, becoming a spiny bur in fruit. 3. Castanopsis. 
1. PASANIA. Tan-Bark OAK. 
1. PasaNIA DENSIFLORA (Hook. & Arn.) Oerst. in Kloeb. Vidensk. 
Meddel. 84. 1866. 
Quercus densiflora Hook. & Arn. Bot. Beech. 391. 1841. 
Type locality: “California.” First collected by Douglas. 
Distribution: The tan-bark oak extends from the Umqua 
Valley of southern Oregon southward through the Coast Ranges 
to Santa Barbara County, and on the western slopes of the Sierra 
Nevada as far south as Mariposa County. ‘Transition. 
Specimens examined: La Cumbre Peak, Santa Ynez Moun- 
tains, Abrams 4310. 
