This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
A branching shrub, 4°-15° high, the twigs glabrous or sparingly pubescent. Leaves oval, elliptic or sometimes obovate, wider and shorter than those of the preceding species, permanently more or less soft-canescent and pale beneath and stiff-hairy or pubescent on the veins, varying to nearly glabrous, the margins ciliolate-serrulate; pedicels glandular; flowers rose-color to white, very fragrant, expanding with or before the leaves; corolla limb often 2' broad, about equalling the rather stout, densely glandular but scarcely viscid tube; stamens slightly exserted; capsule linear-oblong, glandular, 6"-8" long.
Azalea lutea L. Sp. PI. 150. 1753. A. calendulacea Michx. Fl. Bor. Am. 1: 151. 1803. Rhododendron calendulaceum Torr. Fl. N. & Mid. U. S. 425. 1824.
A shrub, 4°-15° high, similar to the preceding species', the twigs mostly glabrous. Leaves obovate or oval, permanently more or less canescent or tomentose beneath, glabrous, or with some scattered hairs above, the margins ciliolate-serrulate; pedicels short, pilose or glandular; flowers orange-yellow or red, very showy, slightly fragrant, expanding before or with the leaves; corolla-tube about the length of the nearly regular limb, glandular-pilose, the limb often 2' broad; stamens long-exserted; capsule linear-oblong, about 8" high, erect, more or less pubescent.
Rhododendron arborescens Torr. Fl. N. & Mid. U. S. 425. 1824.
A shrub, 8°-20° high, glabrous or nearly so throughout. Leaves obovate, oblanceolate or oval, acute at both ends or sometimes abruptly acuminate at the apex, manifestly petioled, firm, bright green and shining above, light green beneath, 2'-4' long, fragrant in drying, the margins ciliate; flowers white, or tinged with pink, very fragrant, the limb nearly regular, 1 1/2'-2' broad, about as long as the slender glandular tube; pedicels short, glandular; stamens and style red, long-exserted; capsule oblong, densely glandular, 6"-8" long.
In woods, southern Pennsylvania to Georgia and eastern Tennessee. Ascends to 2500 ft. in North Carolina. Smooth honeysuckle. June-July.
Azalea viscosa L. Sp. Pl. 151. 1753.
Rhododendron viscosum Torr. Fl. N. & Mid. U. S. 424. 1824.
A shrub, 1°-8° high, usually much branched, the twigs hairy. Leaves obovate-oblong to oblanceolate, 1'-4' long, very short-petioled, obtuse and mucronulate or acute at the apex, narrowed at the base, glabrous or with a few scattered hairs above, more or less bristly hairy on the veins beneath, ciliolate, green on both sides, or glaucous beneath; flowers white, or sometimes pink, fragrant, later than the leaves; pedicels glandular, or bristly-hispid; corolla 1 1/2-2' long, the limb 1'-2' broad, more or less 2-Hpped, much shorter than the slender, very viscid, densely glandular tube; capsule 5"-7" high, glandular-bristly.
In swamps, Maine to Ohio, Arkansas. Florida and Texas. Consists of several races differing in pubescence, size and shape of leaves and color of flowers. Clammy azalea. Meadow-pink. White or clammy honeysuckle. June-July.