Judd, W.S. & Kron, K.A. (1995) A Revision of Rhododendron VI. Subgenus Pentanthera (Sections Sciadorhodion, Rhodora and Viscidula). Edinburgh Journal of Botany 52(1):27
Verified by:
Shrub to small tree to 2.5(-5.5)m tall; bark thin, flaky or longitudinally
shredding; young twigs pale to reddish brown, very sparsely covered with multicellular
eglandular and gland-headed hairs, very sparsely to sparsely covered with short
unicellular hairs, becoming glabrous with age; new foliage shoots arising from axillary
buds associated with foliage leaves of previous year's shoot (i.e. below terminal bud), and some terminal buds. Vegetative bud scales glabrous to moderately unicellular-pubescent abaxially and sometimes with scattered multicellular gland-headed hairs, especially near apex, sparsely to moderately unicellular-pubescent adaxially, especially near apex, and sometimes with a few multicellular gland-headed hairs near apex; margin fringed with unicellular hairs with intermixed gland-headed hairs, occasionally also with a few eglandular hairs near apex; lowermost scales sometimes with aristate apices or rudimentary blades. Leaves deciduous, dark green adaxially, pale green abaxially, turning red in autumn, alternate (with internodes becoming more closely spaced towards tip of shoot). Blade membranaceous, elliptic to obovate, 2.3-17 x 0.8-5.5cm; base cuneate to attenuate; apex acuminate, with a short mucro; midvein strongly raised and prominent abaxially, the secondary veins slightly raised abaxially; adaxial surface, including midvein, sparsely covered with multicellular gland-headed and eglandular hairs, glabrescent, the midvein unicellular-pubescent; abaxial surface with scattered multicellular gland-headed hairs, the midvein with scattered gland-headed and longer eglandular hairs, the secondary veins with gland-headed hairs only; margin entire to undulate, with widely scattered to definite fringe of multicellular eglandular hairs; petiole 3-15mm long, sparsely unicellular-pubescent adaxially, and with scattered multicellular gland-headed and eglandular hairs, the base of petiole often expanded into a broadened point of attachment, forming a ± triangular slight protuberance below terete portion. Flower buds larger than vegetative buds, more frequently unicellular-pubescent abaxially, and with portion of margin often completely glandular. Flowers appearing before the leaves; inflorescence an umbellate raceme of 5-15 flowers. Pedicels 5-26mm long, moderately covered with multicellular gland-headed hairs and sparsely to moderately unicellular-pubescent. Calyx lobes broadly subovate to narrowly triangular-Ungulate, 0.3-8.5mm long (often extremely variable, even within a single flower), 1.2-2mm wide; apex rounded; margin fringed with multicellular gland-headed hairs; adaxial surface glabrous; abaxial surface + glabrous to with a few multicellular gland-headed hairs. Corolla pink to occasionally white, with orange-brown to red spots on the upper 3 lobes, fragrant, zygomorphic, broadly rotate-funnelform, appearing ± 2-lipped due to more extensive fusion of the upper 3 lobes and the 2 flaring lower lobes being slightly longer, the tube much shorter than the limb and gradually expanding into it; upper corolla lobe 1-1.8 x 0.8-1.3cm; lateral lobes 1.4-2.4x0.8-1.4cm; lower lobes 1.5-2.6 x 0.8-1.3cm; corolla tube 0.4-0.8cm long; outer and inner surfaces of corolla glabrous. Stamens (5-) 7, declinate, variable in length, 1.2-3.7cm long, the shorter stamens included, longer ones exserted; filaments glabrous throughout their entire length. Ovary 3-5mm long, sparsely to moderately covered with multicellular gland-headed hairs; style declinate, 2-3.8cm long, glabrous to with a few multicellular gland-headed hairs near base. Capsules ovoid to oblong-ellipsoid and slightly grooved, 0.9-1.7 x 0.3-0.6cm, sparsely to moderately covered with multicellular gland-headed hairs. Seeds brown, angular-ellipsoid, 1-1.7 x 0.4-0.6mm; testa tightly appressed to body, with cells at each end elongated, bulging, and fused to form ± stellate tails 0.2-0.5mm long, the cells covering central portion of body elongate and non-bulging, those along angles often ± bulbous and expanded (similar to those of tails) and often forming a slight fringe. Cotyledons lacking multicellular hairs and with venation represented by midvein and a small number of poorly developed secondary veins. 2n=26 (Sax, 1930).
United States, North Carolina
Bogs, thickets and deciduous or coniferous forests
Azalea vaseyi (A. Gray) Rehder in Moller’s Deutsch. Gartn.-Zeitung. 14: 332 (1899). Biltia vaseyi (A. Gray) Small, Fl. S.E. U.S. 884 (1903). Type: United States, North Carolina, Jackson Co., summit of a balsam mountain c.7mi SW of Webster, 3 vi 1878, Vasey s.n. (holo. GH; iso. NY, US, US (frag.)). Rhododendron vaseyi A. Gray var. album Bean, Trees and Shrubs Brit. Isles 2: 384 (1914). Rhododendron vaseyi f. album (Bean) Rehder in Mitt. Deutsch. Dendrol. Ges. 24: 225 (1916). Type: n.v.
No additional reference available.