(D.Don) Eichler

Description
Tsuga dumosa, the Himalayan hemlock, is a large evergreen conifer distributed across the Himalaya from central Nepal eastward through Sikkim, Bhutan, and northeast India into southern China (Xizang, Yunnan, Sichuan, Guizhou), Myanmar, and northern Vietnam. It is a characteristic component of cool temperate and upper montane forests at elevations of 2,000–3,500 m, where it often forms pure stands or grows in association with Abies, Picea, Acer, and Rhododendron species. The species has been documented at Lambra Kharka in the Gorkha district of Nepal at approximately 3,000 m, near the upper limit of its elevational range.
Tsuga dumosa is a tree attaining 25–40 m in height with a trunk up to 1.5 m in diameter, bearing a broadly conical to irregular crown. The bark is dark greyish-brown, deeply fissured and scaly on mature trees. Leaves are linear, flattened, 10–25 mm long and 2–3 mm wide, with a rounded or emarginate apex, dark glossy green above with two conspicuous white stomatal bands beneath, arranged in a pectinate (comb-like) pattern on lateral shoots. Male strobili are small, axillary, and globose. Female seed cones are pendulous, ovoid to oblong, 1.5–2.5 cm long, with thin, rounded cone scales that open at maturity to release two small winged seeds per scale. The cones mature in a single season.
Tsuga dumosa is the sole Himalayan representative of the genus Tsuga, which comprises approximately nine species with a disjunct distribution between eastern Asia and North America. Phylogenetic studies place it sister to the East Asian T. chinensis complex. The species is of considerable ecological importance as a canopy dominant in Himalayan temperate forests, providing critical habitat for epiphytic bryophytes, lichens, and orchids. Its timber is locally valued for construction. While not currently assessed as threatened globally, localized deforestation and climate-driven upward range shifts pose potential concerns for some populations.
Author: (D.Don) Eichler · Sources: POWO (Kew), GBIF, Flora of China Vol. 4, Flora of Bhutan Vol. 1, Farjon: A Handbook of the World's Conifers (2017)
















