Name

Pinus mugo Turra, Giorn. Ital., ed. Grisel. 1: 152 (1764).
[Dwarf mountain pine]

Description

Habit: A small tree or low multi-stemmed shrub from 2 m to at least 15 m tall, depending on variety. Usually bushy with numerous, spreading, erect branches.

Bark: Thin and smooth in younger trees. On older trees slightly fissured and broken into irregular small, curled-up plates. Varies from pinkish to brownish grey.

Foliage: Needles in pairs, 1.4-8 cm long, 1-2 mm wide; usually blue-green to dark green, occasionally yellow-green, straight or slightly curved, occasionally twisted; usually densely set and forward pointing. Leaf sheath persistent; on young needles 6-15 mm long and conspicuous, white on upper part and light brown at base of needles; reducing to 3-7 mm and becoming grey-brown on older needles. Needles persist for 5 years or more.

Branchlets: Yellow-green at first, soon becoming greenish brown and later dark grey-brown to purplish brown, without hairs, shiny, stout, and ridged. Leaf bract bases not conspicuous. Spring shoots uninodal.

Winter buds: Ovoid-cylindrical with conical or short rounded tip; light orange-brown, very resinous. Scales closely appressed, rarely with a few scale tips free near the base of bud.

Cones: Usually solitary or in pairs, occasionally in whorls of up to 8; nearly sessile; ripening and opening in second year, occasionally persisting for up to 4 years after opening; ovoid or conical-ovoid; 2-6 cm long, 1.5-2.6 cm wide when closed and 2-5 cm wide when open; symmetrical. Shiny green-brown when young, yellow-brown to dark red-brown at maturity, weathering to grey-brown. Exposed ends of scales slightly convex and ridged. Umbo (central part of exposed scale) grey-brown, occasionally terminating in a minute (less than 1 mm long), fragile prickle.

Seeds: Small, 4-5 mm long, c. 3 mm wide; vary from cream, yellow-brown, or red-brown to almost black, sometimes finely mottled; ovoid or oblong-ovoid, usually quite pointed at one end. Wing 10-15 mm long, 4-6 mm wide, oblong, usually red-brown, sometimes almost transparent.

Notes

The mountain pines, P. mugo and P. uncinata are separated from most other pines by their short, rigid, paired needles, very resinous buds, and small cones. Pinus contorta, the species most likely to be confused with the mountain pines, tends to have longer internodes and a more open habit, darker, less resinous buds, and very prickly cones.

Natural Distribution

Mountainous areas of Europe, from France to Bulgaria and northern Greece.