Fraxinus americana L. White ash, American ash. Family Oleaceae. ITIS Taxonomic Serial Number 32931. USDA PLANTS Symbol FRAM2. TROPICOS # 23000132.
Images Individual leaf. Branchlet with buds. Close-up of buds. Close-up of leaf scar. Herbarium sheet 1. Herbarium sheet 2. Herbarium sheet 3.
Plant habit and life style. Plants Angiosperms, dioecious, (15)2030(50) m tall.
Stems. Pith continuous. Young twigs (1-year-old or less) brown or gray or green or orange or purple or reddish-brown, glabrous or glabrate or pubescent. Twigs (24 years old) glabrous or pubescent. Leaf scars crescent-shaped or half-round or U-shaped, bundle scars numerous, stipule scars absent. Bark of mature trunks furrowed or ridged.
Buds. Buds axillary or superposed or terminal, black or brown or reddish-brown, conic or ovoid or ovoid-conic, blunt, glabrate or pubescent, puberulent, bud scales imbricate.
Leaves. Leaves deciduous, compound, once pinnately compound, petiolate, opposite, 2030 cm long. Leaf upper surface green, glabrous. Leaf lower surface gray or green or white, glabrous or glabrate or pubescent, pilose. Leaflets petiolulate, (5)7(9) per leaf, 515(18) cm long, 37.5 cm wide, lanceolate or oblong or obovate or oval or ovate, leaflet margins entire or crenate or serrate, leaflet apices acuminate or acute or obtuse, leaflet bases cuneate or oblique or obtuse or rounded, leaflet venation pinnate, terminal leaflet present (odd-pinnate). Petioles glabrous or glabrate or pubescent. Rachises glabrous or glabrate or pubescent. Stipules absent.
Flowers. Flowering March or April or May. Inflorescences axillary, fascicles or panicles, flowers stalked. Flowers unisexual or pistillate or staminate, hypogynous. Perianth. Calyx radially symmetric, synsepalous. Sepals 4 per flower, calyx tubes 12 mm long, persistent. Corolla absent. Androecium. Stamens 2(3) per flower, separate. Gynoecium. Ovaries superior, pistils 1 per flower. Gynoecium syncarpous, 2 carpels per flower, styles 1 per pistil, placentation axile.
Fruits. Fruits samaras, (1.5)2.56.5 cm long, brown or tan or yellow or yellow-green, fruit maturation 1 years.
Habitat. Habitat bottomland forests or disturbed and weedy areas or dry-mesic upland forests or mesic upland forests or mixed forest edges or suburban plantings.
Special Diagnostic Characters. Abaxial surface of leaflets papillose (use at least 20x magnification); upper edge of leaf scars often with a deep notch; wing extending along the rounded body of the fruit 1/3 its length or less.
Cite this publication as: ‘Stephen M. Seiberling, Alan S. Weakley, and Peter S. White (2005 onwards). Common Trees of the North Carolina Piedmont: Identification, Descriptions, Illustrations, and Glossary. Version: March 7, 2006. <http://www.ibiblio.org/openkey/intkey/>’.
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