140 THE AZALEAS OF NORTH AMERICA 



generally ovate, obtusish and mucronulate scales. Leaves elliptic or obovate to 

 obovate-oblong, acute or short-acuminate, gland-tipped, cuneate at the base, 



3 to 7 cm. long and 1.2 to 3.3 cm. broad, sparingly pubescent above, densely grayish 

 villose beneath or sometimes thinly villose rarely nearly glabrous except along 

 the midrib, sparingly strigillose on the midrib, ciliolate, thinnish at maturity, usually 

 more or less bluish green or dull green; petioles 2 to 5 mm. long, soft-pubescent and 

 sparingly strigose. Flowers expanding in May with the leaves in usually 5- to 9- 

 flowered umbel-like racemes, fragrant; pedicels 0.5 to 1.5 cm. long, finely villose 

 and glandular-setose; calyx-lobes semiorbicular to ovate, unequal, scarcely exceed- 

 ing 1 mm., finely pubescent, glandular-ciliate; corolla funnel-form with oblique 

 limb, usually bright pink, rarely whitish, the tube 1.5 to 2 cm. long, cylindric, 

 rather gradually dilated toward the apex, covered with a thin villose tomentum 

 interspersed with numerous gland-tipped hairs of unequal length, pubescent inside, 

 the lobes about as long or slightly shorter than tube, ovate, abruptly pointed; 

 stamens little more than twice as long as tube, filaments pubescent below the 

 middle, the anthers about 2 mm. long, ochraceous; style exceeding the stamens, 



4 to 5 cm. long, sparingly or sometimes rather densely pubescent below, purple 

 above; ovary finely covered with a villous pubescence overlaid with numerous 

 appressed white, setose, partly gland-tipped hairs. Capsule oblong, narrowed 

 toward the apex, 1.5 to 2 cm. long, sparingly puberulous and setosely glandular. 



Rhododendron roseum is distributed from southwestern New Hampshire, cen- 

 tral Vermont and southwestern Quebec l through western New York, eastern Ohio, 

 southern Illinois to southeastern Missouri, and through western and central 

 Massachusetts, northwestern Connecticut, northern Rhode Island, New York, 

 Pennsylvania, and northern New Jersey to southwestern Virginia and western 

 Tennessee. Its range lies chiefly west of the Appalachian Mountains, except in 

 the north, and does not extend into the coastal plain. 



This species is closely related to R. nudiflorum and particularly to its variety 

 glandiferum and I was for some time inclined to refer it as a variety to the latter 

 species, as it seems to be connected with it by intermediate forms. It differs, how- 

 ever, in several important characters from typical R. nudiflorum, as in the pubescent 

 winter-buds, the more or less densely villous branchlets, the pubescent bluish-green 

 leaves, in the shorter stamens and in the glandular corolla with larger and broader 

 lobes and a wider tube, and as the two are easily distinguished in their typical 

 forms, I think it better to keep them as distinct species. Glabrescent forms with 

 the leaves pubescent only along the midrib might be confused with R. nudiflorum, 

 but can be distinguished from it by the flowers, the pubescent winter-buds and 

 the finely villous branchlets. Rhododendron roseum has also been confused with 

 R. canescens Don, with which it agrees in the pubescence of the leaves, but differs 

 in the shorter, gradually dilated pilose-glandular corolla-tube, in the shorter sta- 

 mens and in the thinner, not reticulate leaves. 



This species was first mentioned in 1787 as a variety of Azalea nudiflora "with 

 broad rough leaves" by Wangenheim (Beytr. Forstwiss. 68), who observed it in the 

 state of New York. When it was introduced into cultivation cannot be stated with 

 certainty. It may be one of the varieties mentioned by Aiton in 1789, and without 

 doubt Pursh's specimen from Cacapoon Springs near Winchester, West Virginia, 

 referred by him to R. canescens belongs here. According to a note by Loudon (Arb. 

 Brit. II. 1143) this has been found in Virginia "on the mountains of the Cacapoon 

 Springs, near Winchester, where it forms a shrub growing 3 feet or 4 feet high and 

 producing its rose-coloured flowers in May and June. Introduced in 1812 and 



1 Near Hull, Quebec, June 5, 1916, John Dunbar (Herb. Park Dept., Rochester. 



N. Y.) 



