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..
Erect mostly tall branching shrubs, with alternate thin deciduous leaves. Flowers large, white, purple, yellow, pink, or orange, in terminal umbels developed from cone-like scaly buds. Calyx small or minute, 5-parted. Corolla funnelform, the tube mostly narrow, the limb nearly regularly 5-lobed or somewhat 2-lipped. Stamens 5 (rarely 10), exserted, usually declined; anthers awnless, attached to the filaments by their backs, the cells opening by terminal pores; styles slender, declined, exserted. Ovary 5-celled; ovules numerous in the cavities. Capsule oblong or linear-oblong, 5-celled, septicidally 5-valved from the summit, many-seeded. [Greek, dry, from the habitat of one of the original species.]
About 40 species, natives of North America and Asia. Besides the following, another occurs on the Pacific Coast and 2 or 3 in the Southern States. Type species: Azalea indica L. The genus is included in Rhododendron by some authors. Flowers expanding before or with the leaves.
Flowers pink or white. | ||
Leaves strigose on the midrib beneath; corolla-tube hirsute. | 1. | A, nudiflora. |
Leaves canescent beneath; corolla-tube glandular. | 2. | A. canescens. |
Flowers orange, yellow or red; leaves canescent beneatlu | 3. | A. lutea. |
Flowers expanding later than the leaves. | ||
Leaves shining, glabrous beneath. | 4. | A. arborescens. |
Leaves strigose on the midrib beneath. | 5. | A. viscosa. |
Fig. 3215
Azalea nudiflora L. Sp. Pl. Ed. 2, 214. 1762.
R. nudiflorum Torr. Fl. N. & Mid. U. S. 424. 1824.
A shrub, 2°-6° high, branched above, often simple below, the twigs glabrous, or with stiff hairs. Leaves oblong or obovate, acute at both ends, short-petioled, hairy on the midrib and sometimes on the lateral veins beneath, glabrous or with a few scattered hairs above when old, sometimes canescent on the lower surface when unfolding, 2-4' long, the margins ciliolate; pedicels strigose, 4"-7" long; flowers pink to nearly white, expanding before or with the leaves, faintly odorous, the limb somewhat 2-lipped, 1 1/2' 2' broad, shorter than the narrow tube, which is pilose-pubescent and little or not at all glandular; stamens much exserted; capsule linear-oblong, strigose, 8"-9" long, erect.
In dry sandy or rocky woods and thickets Massachusetts to Illinois, south to Florida and Texas. Ascends to 3000 ft. in Virginia. Reported from Canada and from Maine. Swamp or election-pink. Mayflower. Early, purple or swamp-honeysuckle. River-pink. April-May.
 
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