平卧怒江杜鹃 ping wo nu jiang du juan

Rhododendron prostratum W. W. Smith, Notes Roy. Bot. Gard. Edinburgh 8: 202. 1914; R. chameunum I. B. Balfour & Forrest; R. charidotes I. B. Balfour & Farrer; R. cosmetum I. B. Balfour & Forrest; R. saluenense subsp. chameunum (I. B. Balfour & Forrest) Cullen.

Dwarf creeping shrubs, (0.05–)0.1–0.3(–0.6) m tall. Leaf blade 0.7–1.7 cm; adaxial surface shiny, scales absent when mature, lacking strap-shaped setae. Calyx with abaxial scales sparse or absent, pubescent or nearly glabrous; corolla 1.4–2.5 cm.

Rhododendron thickets on rocky slopes, shrubby meadows on high mountains; (3300–)3800–4800 m. NW Yunnan.

Cubey (A cytological and morphological taxonomic study of Rhododendron L. subsection Saluenensia. PhD thesis, University of Liverpool. 2003) maintained the name R. saluenense subsp. chameunum for this taxon, implying that there is a geographical separation in the distributions of var. saluenense and var. prostratum. From the above descriptions it may be seen that var. prostratum generally occurs at higher altitudes than does var. saluenense.