1. Tsuga canadensis (L.) Carrière (eastern hemlock)
Map 79
Trees to 15(–30) m tall. Trunks with orangish brown to grayish
brown bark, the surface breaking into scaly plates and/or furrowed. Twigs pale
brown to gray or yellowish brown, hairy. Leaves alternate, appearing more or
less 2-ranked, 8–20 mm long, linear, flattened, the tip rounded, the base
tapered to a short, usually twisted or bent petiole. Microstrobili globose,
yellow. Megastrobili conelike, woody or the scales somewhat papery, 1.2–2.0 cm
long, ovoid to broadly elliptic in outline, straight, dehiscing the first
season, but persistent through the winter, the cone eventually shed intact.
Cone scales obovate to circular, rounded at the tip, light green, turning light
brown or grayish brown at maturity, not shiny. Seeds winged, 0.8–1.0 cm long
(including the wing), the wing much longer than the rest of the seed. 2n=24.
Pollen shed March–April.
Introduced, widely planted, but thus far reproducing only at a
single site in Oregon County (northeastern U.S. west to Wisconsin, Indiana, and Alabama; Canada). Mesic upland forests and bluffs near homesites.
Eastern hemlock is included in the flora based upon a single
collection from Oregon County, where it has spread from an old homesite up a
steep, north-facing slope and along adjacent bluffs. The species requires a
rich, sheltered site to survive. Elsewhere in the state, individual trees may
be encountered, but these invariably were planted and are not reproducing.