Amongst the comparatively few deciduous conifers, the larches stand out as peculiarly well marked and distinct. They are all trees of timber-producing size, forming an erect, tapering trunk, carrying usually a cone-shaped head of horizontal branches upturned at the ends, the branchlets pendulous. As in the cedars, the branchlets are of two kinds: (1) elongated slender ones, growing from a few inches to 2 ft or more yearly, and bearing the leaves singly and spirally; and (2) short, spur-like ones which lengthen a minute fraction of an inch annually, and bear numerous (20 to 40) leaves crowded in a terminal tuft. Leaves linear or needle-like, falling in autumn. Flowers unisexual, both sexes appearing on the one tree. Males globose to cylindrical, made up of numerous yellow-anthered, short-stalked stamens. Females erect, globose, usually red, developing into a cone composed of thin, concave, rounded, very persistent, woody scales; bracts either protruded or included. Seeds in pairs on each scale, winged, ripening and falling the first autumn. Of its nearest allies, with a similar leaf arrangement, Pseudolarix differs in the much larger, more woody cone-scales falling away early from the central axis; Cedrus is, of course, evergreen, and its cones much larger.
The larches are widely spread over the cool parts of the northern hemisphere, often in mountainous regions. They like a fairly good loamy soil, and an abundant rainfall. One species, L. laricina, succeeds in damp spots, but the rest like a well-drained site. They should always, if possible, be raised from seeds, which should be sown evenly and thinly, and slightly covered with soil – the common larch out-of-doors, usually in raised beds not more than 4 ft wide to facilitate weeding, the rarer ones in unheated frames for better protection. They may be planted out permanently at 11⁄2 ft high and upwards. Rarer sorts can be grafted in spring on seedlings of the common larch.