There are no active references in this article.
Tree to 12 m. Branchlets stout, shiny, 5–7 mm in diameter. Buds rounded. Leaves 12–21 cm long, with 8–10 pairs of leaflets. Leaflets oblong, 2.5–6 1–1.5 cm, margins entire or remotely toothed in upper third to half, apex mucronate, with pale brown hairs persisting on the veins beneath. Stipules stalked, large, leafy, persistent, to 1.5 cm across, clasping the bud and shoot. Flowers pink, in dense corymbs. Fruit 0.8–1 cm, ripening through red to pink then white, persisting only a short time; calyx lobes triangular, pointing forwards; carpels (four to) five, forming a conical protuberance below calyx lobes. Sexual diploid. McAllister 2005a. Distribution BHUTAN; INDIA: Sikkim; NEPAL. Habitat Abies-Rhododendron forest near the treeline and above. USDA Hardiness Zone 6. Conservation status Not evaluated. Cross-reference B435.
Sorbus arachnoidea is common in the shrub zone between the top end of the Abies forest and the Rhododendron moorland from east Nepal to Bhutan. Beer 404, collected in Nepal in 1971, was probably the first introduction, but it has been firmly established in cultivation since the 1980s from Ron McBeath’s collection (no. 1118) from east Nepal in 1981. From Bhutan, KR 1247, 1438, 1447 and 1487 are also in cultivation. It is related to S. insignis, and like that species, is noticeable for its stout shoots and persistent stipules, but the leaves tend to burn off rather than assume good autumn colours (K. Rushforth, pers. comm. 2008).
Allied to S. arachnoidea is S. longii Rushforth, which is included in S. arachnoidea by Long (1987) but differs in the more slender shoots and smaller leaves (Rushforth 1991). Sorbus longii was first introduced by Hedegaard in 1977 (under his number 350) to Hørsholm, Denmark, from the Milke Danda ridge, Nepal, and subsequently by Keith Rushforth from Bhutan (KR 1423, 1611). In Bhutan it is the commonest rowan in the forest zone dominated by Abies densa, and is also found in Picea spinulosa and Juniperus recurva forest. The character of the fruits dropping as soon as ripe and the absence of strong autumn colour limit the horticultural desirability of this species (K. Rushforth, pers. comm. 2008).