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| | Classification of the genus Pinus |
 | | There are three main categories of pine trees, the subgenus Strobus (white or "soft") pines, the subgenus Ducampopinus (pinyon, foxtail and lacebark pines), and the subgenus Pinus (yellow or "hard") pines. |
 | | Generally, a very ancient group with diverse morphology, and most species with small relictual ranges; most are highly specialised to difficult sites where few or even no other trees will grow (one or more of low rainfall; infertile rocky sites; serpentine; limestone; very high altitudes); most are rare and many are endangered. |
 | | The defining morphology: A heterogenous group, sharing nothing beyond the main features of the subgenus (above), they would be better treated in several sections (mostly yet to be formally named) corresponding to the subsections below, which are ancient groups that diverged from each other long ago. |
| www.pinetum.org /Lovett/classification.htm (1253 words) |
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