Pinus L.
Evergreen, resinous trees or, less commonly, shrubs; bark usually rough and fissured; branches regularly whorled, with long shoots bearing scale-like lvs; short shoots comprising a fascicle of 2, 3 or 5, very rarely 1, 4 or 6-8 lvs (needles), the fascicle base invested by a partly persistent or deciduous sheath (usually at least partly deciduous by the end of the first year). Winter buds terminating shoots usually conspicuous, cylindric to ovoid, with numerous imbricate scales, generally entire or somewhat erose, often resinous. Lvs needle-like, green, grey or glaucous, with 1-2 vascular bundles; resin ducts 2 or more. ♂ strobili (cones) replacing short shoots at base of the current season's long shoot, usually densely clustered, catkin-like, mainly cylindric, yellow to red prior to dehiscence. ♀ cones (called conelets before fertilisation) subterminal or lateral, replacing short shoots, ripening in second or third year, purple, green or brown when young, mostly light to dark brown at maturity, often erect when young, later spreading to pendulous or recurved; bracts scales very small, hidden, 0 in mature cone; ovuliferous scales forming main part of cone, very variable, closing after pollination; apophysis (apical part) with an umbo (protuberance) distally, sometimes flattened, becoming hard or remaining soft (semi-woody), often with a prickle; ovules 2 to each scale. Mature cone dehiscent or remaining closed, persistent or soon falling, sometimes leaving behind basal scales, symmetric or asymmetric. Seed usually prominently and unilaterally winged, occasionally wingless.
Key
c. 100 spp., mostly temperate regions, a few in subtropical and tropical regions as far S. as Java and C. America. Naturalised spp. 13.
Nearly all the spp. of pine have been introduced to N.Z. for trial. With one exception the pines described below are in subgen. Pinus, the hard cone pines. The exception is P. strobus, in subgen. Haploxylon (Koehne) Pilger, soft cone pines. This subgen. is easily distinguished by the lvs having only 1 vascular bundle and deciduous sheaths, and soft (semi-woody) narrow cones with terminal umbos, as opposed to spp. of subgen. Pinus, which have 2 vascular bundles in the lvs, ± persistent lf sheaths, and hard to extremely hard, usually broad, woody cones with dorsal umbos. Mature cones of Pinus spp. are illustrated in Plates 3 and 4.
