General: Large, deciduous, spreading tree up to 30 m tall; branches greenish barked, smooth; older bark greyish-brown, ridged and often covered with lichens and mosses.
Leaves: Opposite, 10-30 cm wide, deeply 5-lobed, tips abruptly sharp-pointed, dark green above and paler green below, turning yellow in fall, stalks with milky juice when cut.
Flowers: Inflorescence racemose with male and female flowers on the same plant; numerous on short stalks, appearing with or before the leaves; petals greenish-white,
Fruits: Winged, in pairs, 3-6 cm long, yellowish-brown, hairy, pairs attached in a V-shape.
2. Flowers 10-50; inflorescence racemose or in panicles; trees up to 30 m tall.
3. Leaves grey, white or purplish below, the stalks without milky juice when cut; inflorescence in long, hanging panicles; fruits glabrous ..........A. pseudoplatanus
3. Leaves green below, the stalks with milky juice when cut; inflorescence racemose or in stiff, more or less erect panicles; fruits glabrous or hairy.
4. Leaves lobed beyond the middle, the tips abruptly sharp-pointed; inflorescence racemose; fruits hairy ..........A. macrophyllum
4. Leaves not lobed beyond the middle, the tips bristlelike; inflorescence in stiff, more or less erect panicles; fruits glabrous ..........A. platanoides
2. Flowers usually less than 10; inflorescence umbellate or corymbose; plants usually shrublike and less than 10 m tall.
5. Leaves 3- to 5-lobed, glabrous to sparsely glandular short-hairy; sepals green.......... A. glabrum
5. Leaves 7- to 9-lobed, soft-hairy beneath and often hairy above; sepals red ..........A. circinatum
Habitat / Range
Moist to mesic forests and open slopes in the lowland and montane zones; common in SW BC west of the Coast-Cascade Mountains; S to CA, disjunct in ID.
The table below shows the species-specific information calculated from original data (BEC database) provided by the BC Ministry of Forests and Range. (Updated August, 2013)
A shade-intolerant, submontane to montane, Western North American deciduous broadleaved tree distributed more in the Pacific than the Cordilleran region. Occurs in maritime to submaritime cool mesothermal climates on fresh to very moist, nitrogen-rich soils (Moder and Mull humus forms). Its occurrence decreases with increasing elevation, latitude, and continentality. Common in pure or mixed-species stands (usually with red alder or black cottonwood) on alluvial, seepage, and stream-edge sites; occasional on water-shedding sites; dominant in primary succession on fragmental colluvial soils. This fast -growing tree regenerates abundantly from stump sprouts in clearings, thus hindering regeneration and growth of conifers. Its calcium-rich bark supports well developed corticolous moss communities. Characteristic of young-seral forests.
