Kindly sponsored by
Peter Norris, enabling the use of The Rhododendron Handbook 1998
New article for Trees and Shrubs Online.
'Rhododendron blackii' from the website Trees and Shrubs Online (treesandshrubsonline.
Large shrub to 5 m, mostly terrestrial occasionally epiphytic; young stems smooth with a moderate covering of flat brown scales. Leaves 6-8 x 5-7 cm, ovate to orbicular, apex obtuse to rounded, edge smooth or very slightly recurved, base rounded to auriculate, the leaves being virtually sessile; upper surface at first scurfy-scaly, quickly becoming glabrous, the midrib prominently raised above for the basal 1cm, lateral veins about 4 pairs, moderately conspicuous smooth; underneath the midrib raised for about 3/4 of its length, the laterals distinct but only slightly raised, scales, brown well spaced, very variable in size, disc-shaped, sometimes lobed and with small centres. Flowers 4-7 per umbel, horizontal to half hanging; calyx a slightly swollen lobed ring, more or less glabrous; corolla red, slightly curved and narrowly tubular-funnel-shaped, 5.5-6 x 3-4 cm, finely white-scaly on the tube and lobes; stamens 10, grouped on the upper side of the mouth of the flower; ovary silvery scaly and hairy, style with a few simple hairs at the base otherwise glabrous. Royal Horticultural Society (1997)
Distribution Papua New Guinea Western and Southern Highlands
Habitat 2,500-3,400 m
RHS Hardiness Rating H2
Conservation status Least concern (LC)
Similar in floral characters to R. culminicolum but differing in its cordate to auriculate leaves. Named after Michael Black of Grasmere in whose garden Sleumer reported this species growing in 1973. It includes R. sleumeri A.Gilli. Royal Horticultural Society (1997)