4 articles
Tsuga (栂)
Tsuga (栂, tsuga), the hemlocks, is a genus of about 10 Pinaceae conifers native to East Asia and North America, with pendent cones and peglike leaf cushions; it originated in North America in the late Oligocene and spread to Asia via Beringia, and eastern species are threatened by the hemlock woolly adelgid.
Tsuga canadensis
Tsuga canadensis, eastern or Canada hemlock, a shade-tolerant, long-lived conifer of eastern North America; foundation species of ravine and cove forests, now imperiled by the hemlock woolly adelgid and climate change.
Tsuga heterophylla
Tsuga heterophylla, the western hemlock, is a large coniferous tree in the pine family, native from southern Alaska to central California and important for timber.
Tsuga mertensiana
Tsuga mertensiana, mountain hemlock (also alpine hemlock, hemlock spruce), a slow-growing subalpine conifer of the Pacific coast and northern Rockies from Alaska to the Sierra Nevada, reaching 800+ years, with radially arranged needles and large purple cones.