Rhododendron ambiguum

Description with 24 photos. Photo: Finn Bertelsen. A dense, but delicately built, a few meter high, evergreen shrub. Fully hardy. Young shoots with dark scales. Petioles with dark scales, 5 – 8 mm. Leaves elliptic, aromatic, to 6 cm. Apex acute to acute-obtuse, with mucro. Leaf base obtuse to acute. Leaf upper side shiny, dark green, with scattered small scales, c. 140 micrs., 1 – 2 x the diameter apart, pubescent on the midrib. Leaf lower side whitish grey-green, densely lepidote. Scales 0 – 1 x the diameter apart. Two types of scales (magnifying- glass neaded): Large, dark scales, 285 – 340 micrs.; smaller light brown scales, 230 – 240 micrs. Inflorescense with 4 – 5 (6) flowers, with rachis < 5 mm. Pedicels with scattered scales, 8 – 14 mm. Calyx densely lepidote, with exception of the margin, with rounded lobes, 2 – 3 mm. Corolla open funnel-campanulate, zygomorphic, with 5 lobes, light yellow with green spots, with a few external scales, to 40 mm wide and 15 mm deep. Ovary conical, densely lepidote, channelled, with 5 locules, 4 – 5 mm. Stamens 10, unequal, proximally densely hairy-glandular hairy. Style green, upward bend, 30 – 35 mm, with slightly turbinate, bullate stigma, 1.3 mm. Capsules lepidote, cylindrical, 10 -15 mm x 2 – 3 mm. Seeds (CW) 1.3 – 1.6 mm, in the garden specimen 1.6 – 2.0 mm, with tiny floating sacs. Occurrence: C. and W. Sichuan, China, at 2300 – 3300 (-4500) m according to Flora of China efloras org.