黑红血红杜鹃 hei hong xue hong du juan

Rhododendron didymum I. B. Balfour & Forrest, Notes Roy. Bot. Gard. Edinburgh 13: 256. 1922; R. sanguineum subsp. didymum (I. B. Balfour & Forrest) Cowan.

Bud scales usually persistent. Corolla deep blackish crimson; ovary at least partly glandular-tomentose.

Thickets, alpine meadows, rocky slopes; 3000–3800(–4500) m. SE Xizang, NW Yunnan.

Rhododendron sanguineum subsp. atrorubrum Cowan (Notes Roy. Bot. Gard. Edinburgh 20: 69. 1940), described from Xizang, is intermediate between var. didymum and var. sanguineum; it is not formally treated here as its exact status is uncertain.