| General Information |
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| Distribution | The pine genus is the largest in the family, with 111 species, native to all continents and some oceanic islands of the northern hemisphere, chiefly in boreal, temperate, or mountainous tropical regions; reaching its southernmost distribution shortly below the Equator in southeast Asia (Sumatra). Introduced as ornamental and timber trees in much of the southern hemisphere.
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Habit
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Trees or shrubs, aromatic, evergreen; crown usually conic when young, often rounded or flat-topped with age. Bark of older stems variously furrowed and plated, plates and/or ridges layered or scaly. Branches usually in pseudowhorls; shoots dimorphic with long shoots and dwarf shoots; dwarf shoots borne in close spirals from axils of scaly bracts and bearing fascicles of leaves (needles). Branchlets stout, ending in a compound bud with many bud scales. Buds ovoid to cylindric, apex pointed (blunt), usually resinous. Plants monoecious (rarely semi-dioecious).
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Leaves
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Leaves dimorphic, spirally arranged; foliage leaves (needles) (1)2-5(6) per fascicle, persisting 2-12 or more years, terete or ± 2-3-angled and rounded on abaxial surface, sessile, sheathed at base by 12-15 overlapping scale leaves, these (at least firmer basal ones) persisting for life of fascicle or shed after first season; resin canals mostly 2 or more (rarely 0-1; max. c. 20).
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Seeds
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Two seeds at the base of the cone scale, winged, in some the wing vestigial; cotyledons (3)6-14(24).
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Pollen Cone
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Pollen cones numerous and small, in a dense, spikelike cluster around base of current year's growth, mostly ovoid to cylindric-conic, tan to yellow, red, blue, or lavender.
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Seed Cone
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Seed cones solitary to few, maturing in 1.5-2(-3) years, shed early or variously persistent, pendent to ± erect, at maturity conic or cylindric, sessile or stalked, shedding seed soon after maturity or variously serotinous (not opening upon maturity but much later, usually in response to fire); scales numerous, persistent, woody or pliable, surface of exposed apical portion of each scale (apophysis) thickened, with umbo (exposed scale surface of young cone) represented by a scar (sometimes apiculate) or extended into a hook, spur, claw, or prickle; bracts included.
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Chromosomes
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x=12
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Contributor
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David Lorence
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