Description from Flora of China
Rhododendron dauricum Linnaeus subsp. mucronulatum (Turczaninow) Voroschilov; R. dauricum var. mucronulatum (Turczaninow) Maximowicz.
Deciduous multi-branched shrubs, 1–2 m tall; young branches thin and long, sparsely scaly. Petiole 3–5 mm; leaf blade thin, elliptic or elliptic-lanceolate, 3–7 × 1–3.5 cm; base cuneate or obtuse, entire or denticulate; apex acute, acuminate or obtuse; abaxial surface brown, scaly; adaxial surface sparsely scaly. Inflorescences solitary or to 3, subapical, opening before leaves, pseudoumbellate, bud scales persistent. Pedicel 0.5–1 cm, sparsely scaly; calyx 5-lobed, 0.5–1 mm, scaly, glabrous or sparsely setose; corolla funnelform, pale reddish purple, 2.3–2.8 × 3–4 cm, outer surface pubescent; stamens 10, unequal, slightly shorter than corolla tube; filaments pubescent below; ovary 5-locular, densely scaly; style longer than corolla, glabrous. Capsule cylindric, 10–15 × 4–5 mm. Fl. Apr–Jun, fr. May–Jul.
Betula or Larix forests, forest margins. Hebei, Jiangsu, Liaoning, Nei Mongol, Shandong [Japan, Korea, Mongolia, Russia].