Larix Mill. (1754), the larch, is a genus in the family Pinaceae, with 11 species found throughout the colder parts of the northern hemisphere.

Description Trees to 65m, pyramidal and fast-growing when young, regularly growing over 1m per year for 30 years. The leaves are 3–5cm long, deciduous, needle-like, bright green or greyish, with white bands beneath, in whorls on short shoots on the older branches and scattered on leading shoots. Autumn colour is a beautiful orange-yellow. The male flowers are small and often yellow, the females usually red; they are produced in early spring, before the leaves emerge on the long, hanging shoots. Pollination is by wind. The cones are generally small, with rounded scales, 3–4cm long, but to 8.5cm with exserted and reflexing pointed bracts in L. griffithii Hook. fil. Seeds have long wings.

Key Recognition Features The deciduous leaves in whorls and small cones are typical of larches. Bare twigs are pinkish, yellow-brown, or soft orange in winter.

Evolution and Relationships Similar in many characteristics to Cedrus, but that is evergreen and has larger cones. Pseudolarix is closely allied, and is also deciduous, but has open, upright cones.

Ecology and Geography On mountain slopes and in northern bogs. The tamarack, L. laricina (Du Roi) K. Koch, is found all across North America from Newfoundland to Alaska. Other species are found in the Alps, in Siberia, and in the eastern Himalayas.

Comment Larch is valuable for timber, and commonly planted. Its wood is resistant to decay and especially valuable for building boats. It is also used for production of turpentine, and the bark is used in tanning. The hybrid between the European L. decidua Mill. and the Japanese L. kaempferi (Lamb.) Carr., now called L. x marschlinsii Coaz (formerly L. x eurolepis Henry) shows hybrid vigour and is often planted for quick shelter.