Native to (or naturalized in) Oregon:
- Broadleaf evergreen shrub to 6-18 ft (~1.5-5 m) tall, young shoots covered with brownish hairs which spread to the leaf petiole. Leaves are clustered at the ends of each year's growth, narrowly oblong to oblong-lanceolate or obovate, 6-13 cm long and 2-4 cm wide, tip acuminate to obtuse, base rounded or wedge-shaped (cuneate), margin reflexed, upper surface bright green, minutely wrinkled (rugulose) at maturity, without hairs, midrib deeply grooved, lower surface pale green, shining, prominent midrib; petiole 1.5 cm long. Flowers in clusters (raceme umbels) of 7-10, each flower bell-shaped (campanulate), about 5 cm long, white to pale rose, with a deep purple basal blotch, 10 stamens of unequal length, pistil about 3 cm long, stigma small.
- -5° F, early, 2/2/2-3 [quality rating of flower / foliage & plant / performance, based on a 1(poorest) to 5 (best) scale]. Best in light shade.
- Native to China, found in Chongquing, S Shaanxi, SW Sichuan, and NE Yunnan; forests 1700-3500 m.
- There are two forms:
- Rhododendron pachytrichum var. pachytrichum: Leaf blade leathery, narrowly oblong or oblanceolate to obovate, 714 × 24.5 cm; base cuneate or rounded. Style 22.5 cm long. Flowers in MayJun, fruits, AugSep.
- Rhododendron pachytrichum var. tenuistylosum: Leaf blade subleathery, oblong-elliptic, 58.5 × 1.82.7 cm; base cuneate. Style to 4.5 cm long. Capsule furrowed, densely tomentose.
- pachytrichum: pachy, thick; trichum; trichome (hair); with thick hairs
- Federal Way, Washington: Rhododendron Species and Botanical Garden.