2. R. viscòsum, Torr. (Clammy A. White Swamp-Honeysuckle.) Branchlets bristly, as well as the margins and midrib of the oblong-obovate otherwise smooth leaves; calyx-lobes minute; corolla clammy, the tube much longer than the lobes. (Azalea viscosa, L.)—Swamps, mostly near the coast, Canada and Maine, to Fla. and Ark. June, July.—Var. glaùcum, Gray. Leaves paler, often white-glaucous underneath or on both sides, sometimes rough-hairy. N. Eng. to Va.—Var. nítidum, Gray. Dwarf, with oblanceolate leaves green both sides. Mountains, N. Y. to Va.
[+][+] Flowers appearing before or with the leaves.
3. R. nudiflòrum, Torr. (Purple A. Pinxter-flower.) Leaves downy underneath; tube of the corolla scarcely longer than the ample lobes, slightly glandular. (Azalea nudiflora, L.)—Swamps, Canada to Fla., Ill., Mo., and Tex. April, May. The showy flowers vary from flesh-color to pink and purple. There are numberless varieties, some of them with 10 stamens.
4. R. calendulàceum, Torr. (Flame-colored Azalea.) Leaves hairy; tube of the corolla shorter than the lobes, hairy. (Azalea calendulacea, Michx.)—Woods, mountains of Penn. to Ga. May. Covered just when the leaves appear with a profusion of large orange blossoms, usually turning to flame-color, not fragrant.
[*][*] Flower-buds of fewer and early caducous scales; corolla irregular, with short or hardly any tube, anteriorly divided to the base; the limb equalling the 10 stamens and style.
5. R. Rhodòra, Don. Young parts sparingly strigose-hairy (1–2° high); leaves oblong, pale, more or less pubescent; corolla hardly 1´ long, purplish-rose-color, bilabiate, with the posterior lip 3-lobed, the anterior of 2 oblong-linear and recurving nearly or quite distinct petals. (Rhodora Canadensis, L.)—Cool bogs, Newf. and N. Eng. to mountains of Penn.
§ 2. RHODODÉNDRON proper. Leaves coriaceous and persistent; stamens (commonly 10) and style rarely exserted, somewhat declined, or sometimes equally spreading.
6. R. máximum, L. (Great Laurel.) Leaves 4–10´ long, very thick, elliptical-oblong or lance-oblong, acute, narrowed toward the base, very smooth, with somewhat revolute margins; pedicels viscid; corolla bell-shaped, 1´ broad, pale rose-color or nearly white, greenish in the throat on the upper side, and spotted with yellow or reddish.—Damp deep woods, rare from Maine to Ohio, but very common through the Alleghanies from N. Y. to Ga. July.—Shrub or tree 6–35° high.
7. R. Catawbiénse, Michx. Leaves oval or oblong, rounded at both ends, smooth, pale beneath (3–5´ long); corolla broadly bell-shaped, lilac-purple; pedicels rusty-downy.—High Alleghanies, Va. to Ga. June. Shrub 3–6° (rarely 20°) high.
8. R. Lappónicum, Wahl. Dwarf, prostrate in broad tufts (6´ high); leaves (½´ long) elliptical, obtuse, dotted (like the branches) with rusty scales; umbels few-flowered; corolla open bell-shaped, dotted, violet-purple; stamens 5–10.—Alpine summits of northern N. Y. and N. Eng., to the Arctic Coast. July. (Arct. Eu. and Asia.)