2. P. grandidentàta, Michx. (Large-toothed Aspen.) Tree 60–75° high, with smoothish gray bark; leaves roundish-ovate, with large and irregular sinuate teeth, when young densely covered with white silky wool, at length smooth both sides; scales cut into 5–6 unequal small divisions, slightly fringed.—Rich woods and borders of streams, N. Scotia to the mountains of N. C., west to N. Minn. and Tenn.
[*][*] Petioles terete; bracts not silky; stamens 12–60.
3. P. heterophýlla, L. (Downy Poplar.) Tree 40–80° high; leaves ovate with a somewhat truncate or cordate base, obtuse, crenate, white-woolly when young, at length nearly smooth, except on the elevated veins beneath; fertile catkins few-flowered; capsules ½´ long, equalling the pedicels.—Borders of river swamps, Conn. to Ga., and in the west from S. Ind. and Ill. to Ark. and W. La.
§ 2. Styles 2–4, with dilated lobes; capsules large, often thick, subglobose to ovate-oblong, 2–4-valved; bracts mostly glabrous; seeds 1–2´´ long.
4. P. balsamífera, L. (Balsam Poplar. Tacamahac.) Tree 50–75° high, the large buds varnished with a copious fragrant resin; leaves ovate-lanceolate, gradually tapering and pointed, finely crenate, smooth on both sides, whitish and reticulately veined beneath, on terete petioles ½–2´ long; scales dilated, slightly hairy; stamens 20–30; capsule ovate, 2-valved.—Borders of rivers and swamps, N. New Eng. to Mich. and Minn., and far north and westward.—Var. cándicans, Gray. (Balm Of Gilead.) Leaves broader and more or less heart-shaped; petiole commonly hairy. Common in cultivation, but rare or unknown in a wild state.
5. P. monilífera, Ait. (Cotton-wood. Necklace Poplar.) Tree 75–150° high; leaves broadly deltoid, with numerous crenate serratures and narrow very acute acumination, sometimes ovate, rarely cordate, on elongated flattened petioles; scales lacerate-fringed, not hairy; stamens 60 or more; capsules on slender pedicels (4–5´´ long) in long catkins, oblong-ovate, 3–4-valved. (Incl. P. angulata, Ait.)—Borders of streams, western N. Eng. to Fla., west to the Rocky Mts.
Order 105. EMPETRÀCEÆ. (Crowberry Family.)
Low shrubby evergreens, with the foliage, aspect, and compound pollen of Heaths, and the drupaceous fruit of Arctostaphylos, but the divided or laciniate stigmas, etc., of some Euphorbiaceæ;—probably only an apetalous and polygamous or diœcious degenerate form of Ericaceæ,—comprising three genera, two of which occur within the limits of this work, and the third farther south.
1. Empetrum. Flowers scattered and solitary in the axils. Sepals 3, somewhat petal-like.
2. Corema. Flowers collected in terminal heads. Calyx none.