Description from Flora of China
Shrubs, semievergreen, 1–3 m tall; young shoots slender, densely brown-strigose. Summer and winter leaves different. Petiole 3–6 mm, densely coarsely brown-strigose; leaf blade leathery, lanceolate or elliptic-lanceolate to obovate, 1.5–3.6 × 1–2 cm; base cuneate; margin slightly revolute; obscurely obtusely toothed; apex acuminate and mucronate or subrounded; both surfaces densely coarsely brown-strigose or abaxial surface coarsely brown-strigose along midrib, leaf blade otherwise glabrous. Inflorescence 5–8-flowered, rarely more. Pedicel 0.5–0.7 cm, densely red-brown-strigose; calyx obscure, densely red-brown-strigose; corolla narrowly funnelform, purple-red or pale purple, 2–2.5 × ca. 3 cm, tube narrowly cylindric, 12–15 mm; lobes long-lanceolate, ca. 1 cm, apex pointed; stamens 5, subequal, ca. 2.7 cm, exserted; filaments flat, glabrous; ovary ovoid, ca. 3 mm, dark brown, densely strigose; style ca. 2.8 cm, longer than stamens, glabrous. Capsule long-ovoid, up to 6 × ca. 4 mm, densely brown-strigose. Fl. May–Jun, fr. Jul–Nov.
Perhaps var. obovatifolium is not distinct from var. kwangsiense and Rhododendron kwangsiense would be better treated as a subspecies of R. mariae.
From the original description and accompanying plate, Rhododendron tiantangense G. Z. Li (Guihaia 15: 298. 1995), described from Guangxi, is closely allied to R. kwangsiense, differing in having stamens pilose below. The present authors hesitate to confirm its status as a distinct species as they have seen no material; however, they do not agree with the original author’s suggestion of an affinity with R. microphyton.
Open forests, thickets; 1000–1800 m. W Guangdong, N Guangxi, SE Guizhou, W Hunan.