Rhododendron lapponicum

Shrubs, to 0.5(–0.7) m, rhizomatous. Stems prostrate to erect; bark ± smooth to vertically furrowed, shredding; twigs with straw-colored to ferruginous, multicellular, broad-rimmed, peltate scales and unicellular-hairy. Leaves persistent; petiole with broad-rimmed, glandular-peltate scales; blade oblong-elliptic to elliptic, ovate, or obovate, 0.4–2(–2.5) × 0.2–0.7(–0.9) cm, coriaceous, margins entire, plane to revolute, with broad-rimmed scales, apex obtuse to rounded or mucronate, surfaces with conspicuous, straw-colored or golden to ferruginous, broad-rimmed, glandular-peltate scales and unicellular-hairy abaxially. Floral bud scales ferruginous-lepidote, sometimes also unicellular-hairy abaxially, margins ± ciliate, unicellular and multicellular, elongate eglandular-hairy. Inflorescences fasciculate racemes, 3–6-flowered; bracts similar to bud scales. Pedicels 2.5–14 mm, with ferruginous scales and often unicellular-hairy. Flowers opening before development of leaves, erect to horizontal, fragrant; calyx lobes 0.5–2 mm, with ferruginous scales and unicellular-hairy, margins ciliate, unicellular and multicellular eglandular-hairy; corolla rose to purple, sometimes white, without blotch, broadly funnelform, (6.5–)7.5–14(–15) mm, glabrous on outer surface, petals connate (for 3/4+ their lengths), lobes 4.5–8.5 mm, tube gradually expanding into lobes, 1.5–6.5 mm; stamens 5–10, slightly exserted, ± unequal, 7–13 mm; filaments glabrous or proximally unicellular-hairy. Capsules borne on erect pedicels, 4–7 × 2–3 mm, with ferruginous, peltate scales and unicellular-hairy. Seeds without distinct tails; testa closely appressed. 2n = 26, 52.

Phenology: Flowering spring–summer.
Habitat: Arctic and alpine tundra, rocky barrens and heaths or thickets, raised beach ridges, sandy stream banks
Elevation: 0-1900 m

Greenland, Alta., B.C., Man., Nfld. and Labr. (Nfld.), N.W.T., N.S., Nunavut, Ont., Que., Yukon, Alaska, Maine, N.H., N.Y., Wis., Europe (Russia, Scandinavia), Asia (Siberia).

Discussion

Rhododendron lapponicum is known to hybridize with R. tomentosum in Greenland, producing R. ×vanhoeffenii Abromeit.

Selected References

None.

Lower Taxa