Flora of New Zealand Series

contorta pine

Large shrub, or small to medium-sized tree (sometimes large in cultivation); habit erect or spreading. Branches straight or somewhat twisted. Bark reddish brown, grey on surface, fissured and forming small plates. Shoots brown, glabrous. Buds cylindric or cylindric-ovoid, purplish brown, strongly resinous; scales tightly appressed. Lvs 2 per fascicle, (2.5)-3.5-6.5 cm × 0.8-1.5 mm, not or somewhat twisted, usually pointed forward, generally yellowish green; resin canals median; sheath very short after first year. ♂ strobili 5-15 mm long, cylindric or broadly cylindric. Conelets sessile; scales aristate. Mature cones long-persistent, often not opening until long after maturity, subsessile, usually directed downwards or backwards, 3-6 × 2-3.5 cm, ± broad-ovoid; base asymmetric or somewhat asymmetric; apophyses shining yellowish brown or brown before maturity, ± convex; umbo with short, slender, occasionally deciduous prickle. Seed wing asymmetric but almost oblong, c. 1 cm long.

N.: Volcanic Plateau, especially in and around the Tongariro National Park, to almost 1500 m; S.: inland Canterbury (from the Hanmer area to the Mackenzie Basin), Otago, S. Westland, Southland, to c. 1000 m.

Rocky Mountains, N.W. America 1957

Indigenous and introduced scrub, tussock grassland, pasture, open forest.

Contorta pine is the most aggressive naturalised conifer at medium to high altitudes in N.Z. and it has invaded large areas. It has been widely planted in montane areas, the seed often having been sown from the air.

There has been much confusion concerning infraspecific classification within P. contorta and there is considerable variation in the wild N.Z. contorta pine populations. The most thorough study is that of Critchfield, W.B., Geographic Variation in Pinus contorta (1957). The differences among subspp. are mainly in growth rate, branching pattern, the degree of twisting and colour of lvs and shoots, and the size and shape of the cones. Wild plants in N.Z. vary considerably in length and degree of twisting of the lf, as well as in shape, size, symmetry and density of the cone. It is not possible to assign them to subspp., although many probably belong to the variable  subsp. contorta. The use of the name  subsp. latifolia (S. Watson) Critchf. for the wild populations in N.Z. should be avoided. The name subsp. murrayana (Balf.) Critchf. (sometimes as P. murrayana Balf.) has also been used for contorta pine in N.Z. The common name contorta pine is now generally used in this country and has mostly replaced lodgepole pine, a name which in N. America is applied to inland, high altitude populations of P. contorta.