ENUMERATION OF THE SPECIES 125 



glabrous in R. arborescens and R. prunifolium and sometimes nearly glabrous in 

 R. nudiflorum, R. atlanticum, R. viscosum and R. occidentale. The sepals vary in 

 most species from semi-orbicular or nearly obsolete to oval or oblong, but usually 

 are rather small; in R. oblongifolium they are mostly oblong and usually well de- 

 veloped in R. arborescens and R. occidentale. The corolla is usually glandular- 

 pubescent outside, glabrous or nearly glabrous in R. prunifolium, finely villose 

 and nearly destitute of glands in R. oblongifolium and R. canescens, pilose and 

 eglandular in typical R. nudiflorum and in R. speciosum. The tube is in most 

 species pubescent inside, glabrous or nearly so in R. atlanticum, R. viscosum, R. 

 serrulatum, and usually in R. oblongifolium. The color of the corolla is in most 

 species white to pinkish or pink, pale yellow in R. austrinum, bright yellow to 

 scarlet or bright red in R. calendulaceum, bright red in R. speciosum and crimson 

 in R. prunifolium. The stamens are always pubescent, usually for two-thirds of 

 their length. The style is pubescent at the base in most species and only occa- 

 sionally glabrous or nearly glabrous, but always glabrous in R. prunifolium and 

 usually so in R. arborescens. The pubescence of the ovary is mostly villose, more 

 or less overlaid by strigose or setose hairs which are at least partly gland-tipped in 

 R. calendulaceum, occasionally glandless in R. austrinum, R. oblongifolium, R. ser- 

 rulalum, R. viscosum, R. arborescens, but glandless or nearly so in R. speciosum, 

 typical R. nudiflorum, R. canescens, occasionally glandular in R. atlanticum and 

 R. prunifolium. In R. canescens there are often only a few strigose hairs at the 

 base and the whole ovary appears clothed with silky white hairs. The pubescence 

 of the capsule is similar to that of the ovary; the shape varies much in the same 

 species and is generally ovoid-oblong; the most distinct capsule is that of R. 

 canescens, which is slender and nearly cylindric, almost destitute of bristles, but 

 covered with a fine grayish pubescence. 



The species of this section may be divided into four fairly distinct groups. 

 The first group contains R. occidentale, R. calendulaceum and R. speciosum. The 

 corolla is rather large with a tube dilated gradually above the middle, spreading 

 into a wide limb with broad, ovate lobes; the color is bright yellow to scarlet or 

 white to pink and the upper lobe is marked by a large orange blotch. The flowers 

 appear with or in R. occidentale often after the leaves. The second group contains 

 R. roseum, R. austrinum, R. nudiflorum, R. alabamense and R. canescens. The 

 corolla is generally smaller with a narrow cylindric tube rather abruptly dilated 

 at the apex into a distinctly oblique limb with comparatively narrower lobes; the 

 color is white to pink or pale yellow in one species, without a conspicuous yellow 

 blotch; the stamens are distinctly declinate. The flowers appear shortly before 

 the leaves expand or with the leaves. The third group contains R. atlanticum, 

 R. oblongifolium, R. serrulatum, R. viscosum and R. arborescens. The corolla is 

 similar in shape to that of the preceding group but often larger and its color is 

 white to pink without a yellow blotch and the tube is often glabrous inside. The 

 flower-buds are marked by conspicuous rows of long-stipitate glands on the back 

 of the corolla-lobes. The flowers are very fragrant and appear after the leaves 

 are fully grown or with the leaves in R. atlanticum, which thus forms a connecting 

 link with the preceding group. The fourth group contains only R. prunifolium. 

 The flowers are comparatively large and shaped like that of the preceding group, 

 but of crimson color, and appear after the leaves are fully formed. The whole 

 plant including the corolla tube is glabrous except the pedicels and a few hairs 

 on the midrib and veins of the under side of the leaves which are distinctly 

 acuminate, while they are acute to obtusish in all other species of this group. 



Rhododendron occidentale A. Gray, Bot. Calif. 1. 458 (1876) ; Syn. Fl. 

 II. 140 (1878). Behr, Fl. Vicin. San Francisco, 173 (1888). Dippel, 



