Цуга: род хвойных деревьев

Genus of conifers
the genus
Automatic taxobox
| image = Tsuga heterophylla1. jpg
| image caption = Tsuga heterophylla
| taxon = Tsuga
| authority = (Endlicher) Carrière
| synonyms ref = from Japanese 栂 (ツガ), the name of Tsuga sieboldii) is a genus of conifers in the subfamily Abietoideae of Pinaceae, the pine family. The common name hemlock is derived from a perceived similarity in the smell of its crushed foliage to that of the unrelated plant poison hemlock. Unlike the latter, Tsuga species are not poisonous. The genus comprises eight to ten species (depending on the authority), with four species occurring in North America and four to six in eastern Asia.

The two eastern North American species, T. canadensis and T. caroliniana, are under serious threat by the sap sucking insect Adelges tsugae (hemlock woolly adelgid). This adelgid, related to the aphids, was introduced accidentally from eastern Asia, where it is only a minor pest. Extensive mortality has occurred, particularly east of the Appalachian Mountains. The Asian species are resistant to this pest, and the two western American hemlocks are moderately resistant. In North America, hemlocks are also attacked by hemlock looper. Larger infected hemlocks have large, relatively high root systems that can bring other trees down if one falls. The foliage of young trees is often browsed by deer, and the seeds are eaten by finches and small rodents. Old trees are commonly attacked by various fungal disease and decay species, notably Heterobasidion annosum and Armillaria species, which rot the heartwood and eventually leave the tree liable to windthrow, and Rhizina undulata, which may kill groups of trees following minor grass fires that activate growth of the Rhizina spores.

The wood obtained from hemlocks is important in the timber industry, especially for use as wood pulp. Many species are used in horticulture, and numerous cultivars have been selected for use in gardens. The bark of the hemlock is also used in tanning leather. The needles of the hemlock tree are sometimes used to make a tea and perfume.