Pine refers to coniferous trees of the Genus Pinus in the Family Pinaceae. There are about 115 species of Pinus, although different authors accept anything between about 105 to 125 species. Pine trees are resinous and evergreen. They have scale leaves that are soon lost and replaced by needles bundled in clusters of 1 to 5 needles each. Pines are monoecious: having male and female cones on the same tree. Female cones take 2-3 years to mature after arrival of the male pollen grain, with actual fertilization delayed one year.
Pines are native to most of North America, ranging from the Arctic to Mexico and Nicaragua and the West Indies. They occur naturally in Eurasia, ranging from Spain and Scotland east to the Russian Far East, Japan, and the Philippines, and south to northernmost Africa, the Himalaya and Southeast Asia, with one species just crossing the Equator in Sumatra. They are also extensively planted in many parts of the Southern hemisphere.
Pines grow well in acid soils, some also on calcareous soils. A few are able to sprout after forest fires. Some species of pines need fire to germinate and their populations suffer under fire suppression regimes. Several species are adapted to extreme conditions imposed by elevation and latitude (see Whitebark pine and Bristlecone pine).
Pines are commercially among the most important of species used for timber in temperate and tropical regions of the world. The seeds are commonly eaten by birds and squirrels, and the seeds of some species — called "pine nuts" — are sold commercially for cooking and baking. The resin of some species is important as the source of turpentine.
Monterey Pine (Pinus radiata) and other common pine species are often grown commercially as a source of wood pulp for papermaking. This is because they are fast-growing softwoods that can be planted in relatively dense stands, and because their resinous needles inhibit the growth of other plants (e.g. weeds) in the cropping areas. Pine plantations can be at risk for fire damage because pine resin is flammable to the point of a tree being explosive under some conditions.
List of pine species
North American pine species:
Bristlecone pine - 2 species
Digger pine, Foothill pine or Gray pine, Pinus sabiniana
Longleaf pine - P. palustris
Piñon pine - also as Pinyon pine; 5 species
Table Mountain pine
The most common pine species in Europe include Austrian Pine (also known as Black Pine, Pinus nigra), and Scots Pine (Pinus sylvestris). European Pine species include the following:
Austrian pine - P. nigra
Scots pine - P. sylvestris
Mabberley, D.J. 1987. The Plant Book. A portable dictionary of the higher plants. Cambridge University Press, Cambridge. 706 p. ISBN 0 521 34060 8.