Rhododendron cumberlandense E. L. Braun

Rhodora 43:33 (1941)

WFO ID:

IPNI ID:

Verified by:

Description

Shrub or small tree to 2m tall, usually rhizomatous; young twigs reddish brown, sparsely to densely covered with unicellular hairs and multicellular eglandular hairs, rarely glabrous or with only multicellular eglandular hairs. Vegetative bud scales glabrous abaxially; margin unicellular-ciliate. Leaf blade membranaceous, ovate or obovate to elliptic, (3.1-)4.6-7.0(-8.1) x (1.3-)1.8-2.9(-3.5)cm; base acute to oblique; apex acute to obtuse, often mucronate; adaxial surface glabrous, occasionally with sparse multicellular eglandular hairs, the midvein densely covered with unicellular hairs; abaxial surface glabrous, or very sparsely covered with multicellular eglandular hairs usually also glaucous, the midrib sparsely to densely covered with unicellular hairs and multicellular eglandular hairs, rarely with only multicellular eglandular hairs; margin entire, ciliate with multicellular eglandular hairs; petiole (0.2-)0.3-0.5cm long, sparsely to densely covered with unicellular hairs and multicellular eglandular hairs, rarely with only unicellular hairs. Flower bud scales chestnut brown; abaxial surface glabrous; margin ciliate at the apex and glandular below, rarely glandular to the apex. Flowers appearing after the leaves have expanded; inflorescence a shortened raceme of 3 to 7 flowers. Pedicels (0.4-)0.5-0.7(-Q.9)cm long, sparsely to densely covered with unicellular hairs and multicellular eglandular hairs, rarely with multicellular gland-tipped hairs and then the sepals eglandular. Sepals less than 0.1-0.2(-0.3)cm long, often varying in length on the same flower; margins setose with multicellular eglandular hairs, rarely with multicellular gland-tipped hairs and then the pedicels eglandular; abaxial surface sparsely to densely covered with unicellular hairs and multicellular eglandular hairs, rarely with only multicellular eglandular hairs. Corolla red, fragrance acrid, the tube longer than the limb and abruptly expanding into it; upper corolla lobe 1.3ó1.8(ó2.1) x l.l-1.6(-2.0)cm; lateral lobes 1.4-1.9(-2.5) x 0.7-1,2cm; corolla tube (1.4-)1.6-2.1(-2.4)cm long, 0.2-0.3cm wide at base; outer surface of corolla densely covered with unicellular hairs and sparsely covered with multicellular gland-tipped hairs that continue up the corolla lobes; inner surface of corolla densely covered with unicellular hairs. Stamens (4.2-)4.9-6. l(-6.2)cm long, with dense terete or flattened unicellular hairs on proximal (1.7-)2.3-3.0(-3.1)cm of filament, exserted (2.7-)3.1-4.1(-4.3)cm beyond throat of corolla. Style (3.9-)4.5-6.5(-7.2)cm long, exserted (2.8-)3.0-4.9(-5.5)cm beyond throat of corolla, densely covered with unicellular hairs on proximal 0.1-1.7(-2.8)cm; stigma 0. l-0.2cm wide. Ovary 0.2-0.3(-0.4)cm long, 0. l-0.2cm wide at the base, densely covered with multicellular eglandular hairs over dense unicellular hairs, nectary with a crown of dense unicellular hairs. Capsules (1.2-) 1.4-2.3(-2.8) x 0.5-0.7(-0.8)cm, ovate to broadly ovate, sparsely to moderately covered with unicellular hairs and sparsely to densely covered with multicellular eglandular hairs. Seeds pale to dark chestnut brown, ovate or elliptic to fusiform, (1.8-)2.1-3.4 (-4.5) x (0.5-)0.7-l.l(-1.4)mm, body (0.8-)l.l-1.6(-1.9) x (0.2-)0.4-0.6(-0.8)mm; testa expanded and dorsiventrally flattened, surrounding the body, the cells short, end-walls transverse.

Distribution

Western most Virginia and eastern Kentucky in the Cumberland Mountains and Plateau, south through Tennessee to northern Alabama, and east of the Tennessee River Valley in the southern Blue Ridge, along the border of Tennessee and North Carolina, south to northern Georgia. Isolated populations occur in Talladega, Cleburne and Randolph counties in Alabama

Altitude

Habitat

Ridge-tops above 900m, but also occasionally at lower elevations, in mixed mesophytic forests.

Nomenclatural History

Azalea cumberlandense (E. L. Braun) Copeland, Am. Midi. Nat. 30: 533-625 (1943). Type: Kentucky, McCreary Co.: Yahoo Ridge, 15 vi 1935, E. L. Braun 971 (holo. Herb. Braun, n.v.; iso. A).

Notes

References

Kron, K.A. (1993) A Revision of Rhododendron Section Pentanthera. Edinburgh Journal of Botany 50(3):309