Larix laricina, commonly known as the tamarack, hackmatack, eastern larch, black larch, red larch, or American larch, is a species of larch native to Canada, from eastern Yukon and Inuvik, Northwest Territories east to Newfoundland, and also south into the upper northeastern United States from Minnesota to Cranesville Swamp, West Virginia; there is also an isolated population in central Alaska.

Larix laricina is a small to medium-size boreal deciduous conifer tree reaching 15–23 m (49–75 ft) tall, with a trunk up to 60 cm (24 in) diameter. The bark of mature trees is reddish, the young trees are gray with smooth bark. The leaves are needle-like, 2.5 cm (1 in) long, light blue-green, turning bright yellow before they fall in the autumn, leaving the shoots bare until the next spring. The needles are produced in clusters on long woody spur shoots. The cones are the smallest of any larch, only 1–2.3 cm (3⁄8–7⁄8 in) long, with 12-25 seed scales; they are bright red, turning brown and opening to release the seeds when mature, 4 to 6 months after pollination.

Key characteristics:

Tamaracks are very cold tolerant, able to survive temperatures down to at least −62 °C (−80 °F), and commonly occurs at the Arctic tree line at the edge of the tundra. Trees in these severe climatic conditions are smaller than farther south, often only 3 m (10 ft) tall. They can tolerate a wide range of soil conditions but grow most commonly in swamps, bogs, or muskegs, in wet to moist organic soils such as sphagnum, peat, and woody peat.They are also found on mineral soils that range from heavy clay to coarse sand; thus texture does not seem to be limiting. Although tamarack can grow well on calcareous soils, it is not abundant on the limestone areas of eastern Ontario.

Tamarack is generally the first forest tree to grow on filled-lake bogs. In the lake states, tamarack may appear first in the sedge mat, sphagnum moss, or not until the bog shrub stage. Farther north, it is the pioneer tree in the bog shrub stage. Tamarack is fairly well adapted to reproduce successfully on burns, so it is one of the common pioneers on sites in the boreal forest immediately after a fire.

The central Alaskan population, separated from the eastern Yukon populations by a gap of about 700 kilometres (430 mi), is treated as a distinct variety Larix laricina var. alaskensis by some botanists, though others argue that it is not sufficiently distinct to be distinguished.

Tamaracks are easily susceptible to fires, as they have shallow roots and thin bark. The tamarack's shallow root system also leaves it susceptible to being knocked over by high-speed winds. It has also been discovered that abnormally high water levels often kill tamarack stands. Flooding, mainly caused by beaver dams and newly constructed roads, can kill off stands and damage adventitious roots.

Tamaracks are targeted by many species of insects. One of the most prominent damaging insects is larch sawfly, which is non-native. It causes damage across its range and causes defoliation which can kill the trees within 6 to 9 years. To lessen the problem, parasites have been imported to kill the larch sawflies in parts of Minnesota and Manitoba. Another serious defoliator is the larch casebearer (Coleophora laricella). All tamaracks are susceptible to being killed by the larch casebearer, however recently the outbreaks of larch casebearer have been less severe.