Acer spicatum Lam.

TSO logo

Sponsor

Kindly sponsored by
a member of the International Dendrology Society

Credits

Dan Crowley (2024)

Recommended citation
Crowley, D. (2024), 'Acer spicatum' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/acer/acer-spicatum/). Accessed 2024-05-25.

Genus

Common Names

  • Mountain Maple

Other taxa in genus

Glossary

pubescent
Covered in hairs.

Credits

Dan Crowley (2024)

Recommended citation
Crowley, D. (2024), 'Acer spicatum' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/acer/acer-spicatum/). Accessed 2024-05-25.

A deciduous shrub or tree typically to 10 m. Bark grey to reddish brown, smooth, or slightly fissuring with age. Branchlets pubescent at first, pale grey, turning red during first winter, then grey. Buds acute, with two to three pairs of scales, outer scales red, tomentose. Leaves broadly ovate in outline, base cordate to truncate, shallowly three- (-five) lobed, 8–12 × (5–) 8–12 cm, lobes apically acute or acuminate, margins coarsely to sharply serrate with acute teeth, upper surface yellowish green, puberulent at first, lower surface paler, pubescent throughout with short, greyish hairs; petiole 5–8 cm long, reddish or green, glabrous or pubescent, often slightly grooved, broadest at base; autumn colours yellow to scarlet. Inflorescence terminal, erect, racemose-paniculate, pubescent, many flowered. Flowers pale yellow, 5-merous, pistillate towards the base, staminate at apex, peduncles 6–12 cm, pedicels 0.5–1.2 cm, slender, sepals narrow obovate, pubescent on outer surface, petals longer, narrowly spatulate, stamens seven or eight, inserted in the middle of the nectar disc. Samaras 1.2–2 cm long, wings spreading at right angles or acutely. Nutlets ovoid to subglobose. Flowering May to July, after the leaves have emerged, fruiting in July to October (Sargent 1965; Elias 1980; Weakley 2012).

Distribution  Canada Labrador, Manitoba, Newfoundland, Nova Scotia, New Brunswick, Ontario, Prince Edward I., Saskatchewan, Québec, United States Connecticut, Georgia, Iowa, Kentucky, Maine, Maryland, Massachusetts, Michigan, Minnesota, New Hampshire, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, Tennessee, Vermont, Virginia, West Virginia, Wisconsin

Habitat Along mountain streams, ravines or in woodlands on rich, moist soils in the understory in mixed forests, often at high elevations. Common associates include Acer saccharum, Betula alleghaniensis, Fagus grandifolia and Liriodendron tulipifera.

USDA Hardiness Zone 3-6

RHS Hardiness Rating H7

Conservation status Least concern (LC)

Acer spicatum belongs to a group of seldom grown maples, restricted largely to collections. It is short-lived and relatively unspectacular in both form and seasonal interest, though Jacobson (1996) notes that, in North America at least, its autumn colour is highly valued. Unsurprisongly hardy, given its mountain habitat to which its common name relates, it has been in cultivation in Britain since 1750 when it was introduced by Archibald Campbell, Duke of Argyll (Bean 1976).

Within its native range it is compared morphologically to the sole North American snakebark maple, Acer pennysylvanicum, from which it is quickly distinguished by its unshowy bark, pubescent shoots and smaller, more coarsely toothed leaves, and its many-flowered, upright inflorescences. A. spicatum shares with A. pennsylvanicum isolation from its closest relatives in eastern Asia, A. caudatum and A. ukurunduense. A. spicatum can be separated from these by its leaves that often have three prominent lobes subtended by two smaller, basal lobes, whereas its Asian relatives are prominantly five-lobed, also with two additional basal lobes.

Though at least historically often available in the North American nursery trade (Jacobson 1996), other maples are evidently preferred and no selections of the species appear to be in circulation. However, it is advocated for use by Sjöman & Anderson (2023), who praise the value of its flowers for pollinating insects though acknowledge a general lack of current availability.

The UK and Irish Champion Acer spicatum grows at Glasnevin, Ireland, where it was measured at 11 m tall in 2012 and some 3 m taller than its closest competitor, at Queenswood Country Park, Herefordshire, measured in 2018 (The Tree Register 2024). Recent introductions to UK collections include plants collected as seed under CRDL 30 in West Virginia in 2006, and several accessions of known wild origin at the Royal Botanic Garden Edinburgh, which on the whole have not thrived (T. Christian pers. comm.). Of three individuals from CRDL 30 planted in 2010 in Silk Wood, Westonbirt, two have attained 4 m as of January 2024, while the third failed to establish after growing at a rate nearly twice as fast as its neighbours for the first few years (pers. obs.).