A modern reference to temperate woody plants, including updated content from this site and much new material, can be found at Trees and Shrubs Online.

Tsuga

Family

Pinaceae

Common names

Hemlock

A group of eight or ten evergreen trees of great beauty and elegance, represented on both sides of N. America, in China, Japan, and the Himalaya. They have very slender twigs, and short linear leaves, arranged, except in one species (T. mertensiana), mainly in two opposite ranks, each leaf seated on a cushion-like projection (as in Picea), and closely set on the twigs – twelve to twenty-four to the inch. They differ, however, from those of Picea in being always borne on a short but distinct petiole; in Picea they are sessile on the cushions. Cones solitary, rarely more than 1 in. long, and usually pendulous at the end of the twigs. Seeds winged. In places where they thrive, which is where the rainfall is abundant and the soil is deep and well-drained, they are not exceeded in beauty of form by any other evergreen trees. They are best propagated by means of seed; but the Japanese and Chinese species, perhaps the others also, can be propagated by cuttings.


From the Supplement (Vol. V)

A recent work on this genus, by an American authority, is: John C. Swartley, The Cultivated Hemlocks (1984). It is a revision, by Humphrey Welch, of a thesis on T. canadensis and its variations originally submitted by Dr Swartley to Cornell University in 1939, and is still largely devoted to that species.

Species articles