Rhododendron invictum

Description with 21 photos. Photo: Finn Bertelsen. An upright growing, a few meters high, evergreen shrub. Hardy. Young shoots scaly and puberulent. Petiole scaly, puberulent in the groove, slightly villose, crimson, to 10 mm. Leaf blade elliptic to oblong elliptic, coriaceous, strongly aromatic, to 5 cm. Leaf apex acute to acute-obtuse, with mucro. Leaf base cuneate to obtuse. Leaf adaxial side dark green, scattered scaly, reticulate, puberulent along the midrib. Scales 0.5-2 x their diam. apart, 260-295 micrs. Leaf abaxial side pale grey green, scaly. Scales 0.5-2 x their diam. apart, 260-350 micrs. Flower bud scaly, spindle-shaped, terminal. Inflorescence umbel-like with 2-4 flowers. Rachis 2 mm. Pedicel scaly, to 8 mm. Calyx with 5 lobes. Lobes rounded, scaly, ciliate, 2.4 mm. Corolla with 5 lobes, widely funnel-shaped, slightly zygomorphic, scaly on the outside, puberulent in the throat, purple with a yellow, brown spotted field at the base of the uppermost lobe, 50 mm wide, 10 mm deep (long). Ovary conical, channelled, densely scaly, with apiucal setae, with 5 loculi, 4.0-4.5 mm. Stamens 10, unequal in length, longer than corolla, 18-28 mm. Filaments puberous towards base, purple. Anthers pale purple-brown, 1.9-2.9 mm. Style slightly hairy at base, otherwise glabrous, longer than stamens, 30-32 mm, with upwards bent, black-brown, bullate stigma, 1.7 mm. Capsule scaly to 12 mm. Seeds without wings, with tiny floating appendages, 1.5-1.7 mm. Origin: Hand pollinated seeds from Alan Anderson, Scotland ex Jens Nielsen. Native habitat: S Gansu, China at 2400-2800 m according to Flora of China efloras org. Remarks: R. invictum is described as elepidot at the adaxial side of leaves (Davidian 1982, FoC a.o.) The holotype specimen shows only the adaxial side of a half leaf. This half leaf is in part scaly showing white scales (R. Bot. Gard. Edinburgh Herbarium E00010243).