词条 | Pinaceae |
释义 | Pinaceae tree family the pine family of conifers, 11 genera and 210 species of trees (rarely shrubs) native to north temperate regions. Fir (Abies), Keteleeria, Cathaya, Douglas fir (Pseudotsuga), hemlock (Tsuga, with Nothotsuga sometimes segregated), spruce (Picea), golden larch (Pseudolarix), larch, or tamarack (Larix), cedar (Cedrus), and pine (Pinus) contain many species that are sources of timber, paper pulp, oils, and resins. Some are cultivated as ornamentals. Both male and female reproductive structures are borne on the same plant. The needlelike leaves are solitary, in bundles, or on specialized short branches. The pollen-bearing male cones are solitary or clustered and have many spirally arranged scales, each bearing two pollen sacs. The compound, seed-bearing (ovule-bearing) cones also have many spirally arranged scales. Each scale is free from the bract below it and bears two inverted ovules on its upper side. In members of the genus Pinus, the bract tends to become fused to the scale and thus disappears as the cones mature. |
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