Description:

• Highly resinous, monoecious shrubs or trees
• Leaves deciduous or evergreen, usually with resin canals, acicular, linear or oblong, solitary and spirally arranged on all shoots, and later densely grouped on short, lateral, spur shoots, soft, stiff, flexible, rigid or asperous in texture
• Shoots glabrous, pubescent or hairy, usually with distinctive, rhythmic annual growth increments, and scaly, terminal, often resinous buds in resting season
• Cones: male and female usually on same tree, female often appearing later, or borne mostly on higher branches
• Male cones catkin-like, solitary or grouped, axillary, each cylindric with many, spirally arranged microsporophylls with two pollen sacs on lower surface of each; pollen grains with 2 air-bladders
• Female cones solitary, in irregular groups or whorled, erect, suberect or pendent, sessile or shortly stalked, rounded or elongate, frequently large, each with many spirally arranged scales and ± conspicuous bracts; scales each with two ovules on upper (adaxial) surface, leathery or fleshy at first, becoming stiff, woody, flexible, papery or leathery with age, and sometimes highly resinous, maturing in 1-3 seasons and eventually dismembering on tree, or scales opening on tree to release seed
• Seeds winged or unwinged, 2 to each scale; cotyledons of variable number, sometimes many
• x = 12

Nomenclature:

• *Pinus L.
  • Linnaeus: 1000 (1753)
  • Jessop: 42 (1966)
  • Farjon: 13 (1984), no genus description as such, page reference is to reproductive morphology
  • Page: 329 (1990)
  • Perry: 25 (1991)

Distribution & Notes:

• Global: Species ± 80, northern hemisphere, many species cultivated
• Southern Africa: Several occur as escapes and 8 have become naturalised, mainly in the moister parts of the region