3. PTELEA L.
Small unarmed trees or shrubs, with smooth bitter bark, slender terete branchlets, without terminal buds, small depressed lateral buds covered with pale tomentum, and nearly inclosed by the narrow obcordate leaf-scars marked by the ends of 2 or 3 small fibro-vascular bundles, and thick fleshy acrid roots. Leaves alternate or rarely opposite, without stipules, long-petiolate, usually trifoliolate, the leaflets conduplicate in the bud, ovate or oblong, entire or crenulate-serrate, punctate with pellucid dots. Flowers polygamous, on slender bracteolate pedicels, in terminal or compound cymes, greenish white; calyx 4 or 5-parted; petals 4 or 5, hypogynous; stamens 3 or 4, alternate with and as long as the petals, hypogynous, much shorter in the pistillate flower with imperfect or rudimentary anthers; filaments subulate, more or less pilose, especially toward the base; anthers ovoid or cordate; pistil raised on a short gynophore, abortive and nearly sessile in the staminate flower; ovary compressed, 2—3-celled; style short; stigma 2—3-lobed; ovules superposed, amphitropous, the upper ovule only fertilized. Fruit a 2 or 3-celled broad-winged indehiscent samara surrounded by a reticulate wing or rarely wingless. Seed oblong, acute at apex, rounded at base, ascending; seed-coat smooth or slightly wrinkled, coriaceous; cotyledons ovate-oblong.
Ptelea is confined to the United States and Mexico, where four or five species are known; of these one is a small tree. The bark and foliage of Ptelea is bitter and strong-scented and possesses tonic properties.
The generic name is from πτελέα, a classical name of the Elm-tree.
1. [Ptelea trifoliata] L. Hop-tree. Wafer Ash.
Leaves rarely 5-foliolate on vigorous shoots; leaflets sessile, ovate or oblong, pointed, the terminal leaflet generally larger and more gradually contracted at base than the others, entire or finely serrate, covered at first with short close pubescence, becoming glabrous and rather coriaceous at maturity, dark green and lustrous above, pale below, 4′—6′ long, 2½′—3′ wide, with a prominent midrib and primary veins; turning clear yellow in the autumn before falling; petioles stout, thickened at base, 2½′—3′ in length. Flowers appearing in early spring on slender pubescent pedicels 1′—1½′ long, the pistillate and staminate flowers produced together, the staminate usually less numerous and falling soon after the opening of the anther-cells; calyx and petals pubescent; ovary puberulous. Fruit with a thin almost orbicular sometimes slightly obovate wing, nearly 1′ across, on a long slender reflexed pedicel, in dense drooping clusters remaining on the branches through the winter; seeds ⅓′ long, dark red-brown.
A round-headed tree, rarely 20°—25° high, with a straight slender trunk 6′—8′ in diameter, small spreading or erect branches, and slender branchlets covered at first with short fine pubescence, becoming glabrous, dark brown and lustrous, and marked by wart-like excrescences and by the conspicuous leaf-scars; more often a low spreading shrub. Winter-buds depressed, nearly round, pale or almost white. Wood heavy, hard, close-grained, yellow-brown, with thin hardly distinguishable sapwood of 6—8 layers of annual growth. The bitter bark of the roots is sometimes used in the form of tinctures and fluid extracts as a tonic, and the fruit is occasionally employed domestically as a substitute for hops in brewing beer.
Distribution. Generally on rocky slopes near the borders of the forest, often in the shade of other trees; Long Island, New York, Pennsylvania, and westward through southwestern Ontario (Point Pelee) and southern Michigan to southern Iowa, southeastern Nebraska, and southward to Georgia, Alabama, eastern Louisiana and through Missouri and Arkansas to southeastern Kansas, eastern Oklahoma and eastern Texas. A form with leaflets soft-pubescent on the lower surface (var. mollis T. & G.) occurs in the south Atlantic states from North Carolina to Florida.
Often planted as an ornament of parks and gardens.