|Distribution map of native Sorbus americana range.|
The American mountain-ash and related species (most often the European mountain-ash, Sorbus aucuparia) are also referred to as rowan trees.
Sorbus americana is a relatively small tree, reaching 12 metres (40 ft) in height. The American mountain-ash attains its largest specimens on the northern shores of Lake Huron and Lake Superior.
It resembles the European mountain-ash, Sorbus aucuparia.
- Light gray, smooth, surface scaly. Branchlets downy at first, later become smooth, brown tinged with red, lenticular, finally they become darker and the papery outer layer becomes easily separable.
- Pale brown; light, soft, close-grained but weak. Specific gravity, 0.5451; weight of cu. ft., 33.97 lbs.
- Winter buds
- Dark red, acute, one-fourth to three-quarters of an inch long. Inner scales are very tomentose and enlarge with the growing shoot.
- Alternate, compound, odd-pinnate, 6 to 10 inches (15 to 25 cm) long, with slender, grooved, dark green or red petiole. Leaflets 13 to 17, lanceolate or long oval, two to three inches long, one-half to two-thirds broad, unequally wedge-shaped or rounded at base, serrate, acuminate, sessile, the terminal one sometimes borne on a stalk half an inch long, feather-veined, midrib prominent beneath, grooved above. They come out of the bud downy, conduplicate; when full grown are smooth, dark yellow green above and paler beneath. In autumn they turn a clear yellow. Stipules leaf-like, caducous.
- May, June, after the leaves are full grown. Perfect, white, one-eighth of an inch across, borne in flat compound cymes three or four inches across. Bracts and bractlets acute, minute, caducous.
- Urn-shaped, hairy, five-lobed; lobes, short, acute, imbricate in bud.
- Petals five, creamy white, orbicular, contracted into short claws, inserted on calyx, imbricate in bud.
- Twenty to thirty, inserted on calyx tube; filaments thread-like; anthers introrse, two-celled; cells opening longitudinally.
- Two to three carpels inserted in the bottom of the calyx tube and united into an inferior ovary. Styles two to three; stigmas capitate; ovules two in each cell.
- Berry-like pome, globular, one-quarter of an inch across, bright red, borne in cymous clusters. Ripens in October and remains on the tree all winter. Flesh thin and sour, charged with malic acid; seeds light brown, oblong, compressed; cotyledons fleshy.
Native to eastern North America;
- Eastern Canada – New Brunswick, Newfoundland, Nova Scotia, Ontario, Prince Edward Island, Quebec
- Northeastern United States – Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Vermont
- North-Central United States – Illinois [n. (Ogle Co.)], Michigan, Minnesota, Wisconsin. Listed as endangered by the State of Illinois
- Southeastern United States – Appalachian Mountains, Georgia, Maryland, North Carolina, Tennessee, Virginia, West Virginia
The berries of American mountain-ash are eaten by numerous species of birds, including ruffed grouse, ptarmigans, sharp-tailed grouse, blue grouse, American robins, other thrushes, waxwings, jays, and small mammals, such as squirrels and rodents.
American mountain-ash is a preferred browse for moose and white-tailed deer. Moose will eat foliage, twigs, and bark. Up to 80 percent of American mountain-ash stems were browsed by moose in control plots adjacent to exclosures on Isle Royale. Fishers, martens, snowshoe hares, and ruffed grouse also browse American mountain-ash.
Sorbus americana is cultivated as an ornamental tree, for use in gardens and parks. It prefers a rich moist soil and the borders of swamps, but will flourish on rocky hillsides.
After their first winter freeze, the fruits are edible raw or cooked. They can be used to make pie and jelly.
- Botanic Gardens Conservation International (BGCI).; IUCN SSC Global Tree Specialist Group. (2018). "Sorbus americana". IUCN Red List of Threatened Species. 2018: e.T135956666A135956668. doi:10.2305/IUCN.UK.2018-2.RLTS.T135956666A135956668.en. Retrieved 3 May 2020.
- McAllister, H.A. (2005). The genus Sorbus: Mountain Ash and other Rowans. Kew Publishing.
- ITIS Report Sorbus americana
- "Sorbus americana". Tropicos. Missouri Botanical Garden.
- "Conservation Plant Characteristics for ScientificName (CommonName) - USDA PLANTS". plants.usda.gov.
- Keeler, Harriet L. (1900). Our Native Trees and How to Identify Them. New York: Charles Scribner's Sons. pp. 136–140.
- "Sorbus americana". Germplasm Resources Information Network (GRIN). Agricultural Research Service (ARS), United States Department of Agriculture (USDA).
- "Threatened Search Results - USDA PLANTS". plants.usda.gov.
- "Fire Effects Information System".
- "Urban Forest Nursery: Tree Profile for the Red Cascade Mountain Ash". www.urbanforestnursery.com. Retrieved January 31, 2013.
- Elias, Thomas S.; Dykeman, Peter A. (2009) . Edible Wild Plants: A North American Field Guide to Over 200 Natural Foods. New York: Sterling. p. 240. ISBN 978-1-4027-6715-9. OCLC 244766414.
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