Aceraceae (Maple Family)

Mountain Maple,Acer glabrumTorr. var.diffusum(Greene) Smiley. (Fig. 5.11) Shrub to small tree 6–20 ft (2–6 m) in height; twigs whitish gray; leaves simple, palmately lobed; leaf blades 0.6–1 in (1.5–2 cm) long, 0.5–1.1 in (1.2–2.8 cm) wide, with few blunt teeth on lobes; peduncle plus pedicel 0.4–0.8 in (1–2 cm) long; fruit a samara, three to six pairs, 0.8–1.2 in (2–3 cm) long.

Figure 5.11
Mountain Maple.

Distribution. Rare in White-Inyo Range; on rocky slopes between 8,000 and 9,000 ft (2,440 and 2,750 m). Collected from Birch Creek (8,400 ft [2,560 m]), Wyman Creek (8,600 ft [2,620 m]), and Cottonwood Creek (8,700 ft [2,650 m]) drainages.

Mountain Maple prefers moist, shaded habitats near streams and springs or under a canopy. It is the smallest of the Great Basin maples. This variety also grows in the Panamint Mountains and along the eastern Sierra Nevada. It is a favorite deer browse (Lanner, 1984).

Box Elder,Acer negundoL. ssp.californicum(Torr. & Gray) Wesmael. Tree 20–65 ft (6–20 m) in height with broad, rounded crown; twigs slender, pubescent, greenish; leaves pinnately trifoliate, three to five lobes, ovate, 2–4.8 in (5–12 cm) long, coarsely serrate, densely pubescent beneath; flowers unisexual, greenish; pedicels filiform; four to five stamens; samara straw-colored when mature, finely pubescent, 1–1.2 in long.

Distribution. Rare in the White-Inyo Range. Lowland and riparian tree, often introduced. Present at old Roachville town site along Cottonwood Creek at 5,800 ft (1,770 m).

Box Elder occurs throughout North America, but its distribution is patchy, especially in eastern California and the Great Basin. This tree has been widely planted for shade in semi-arid regions. The sap of this tree has been collected as a source of syrup (Lanner, 1984).