![]() ![]() Pollen-bearing male cones are covered with many fertile scales, each of which bears two pollen sacs. Their wood is coarse-grained and usually dark-coloured, with pale, often thick sapwood the sheaths of the leaf clusters are persistent, and the leaves have two fibrovascular bundles.ĭiscover how male gametophytes travel up pine trees to strobili-covered female pine cones to catalyze fertilization as part of the reproductive process in pine trees. Hard pines, such as Scotch, Corsican, and loblolly pines, have relatively hard timber, needles in bundles of two or three (rarely, five to eight), cone scales with prickles, and large amounts of resin. Their wood is close-grained, with thin, nearly white sapwood the sheaths of the leaf clusters are deciduous, and the leaves contain a single fibrovascular bundle. Soft pines, such as white, sugar, and piñon pines, have relatively soft timber, needles in bundles of five (less commonly, one to four), stalked cones with scales lacking prickles, and little resin. Pines are softwoods, but commercially they may be designated as soft pines or hard pines. Pine-leaf oil, used medicinally, is a distillation product of the leaves charcoal, lampblack, and fuel gases are distillation by-products. Many pines are cultivated as ornamentals, including black, white, Himalayan, and stone pines, and some are planted in reforestation projects or for windbreaks. Edible pine seeds, which are sold commercially as pine nuts, pignoli, piñons, or pinyons, are produced by several species. The chief economic value of pines is in the construction and paper-products industries, but they are also sources of turpentine, rosin, oils, and wood tars. Like all trees, the plants provide habitat and a variety of other ecosystem services, and pine seeds are an important food source for birds, squirrels, and other animals. Pines and other conifers are key members of the taiga (boreal forests), coniferous forests, and mixed forests throughout the world, and many pine species are iconic or characteristic constituents of a number of specific ecosystems, such as the longleaf pine ( Pinus palustris) ecosystem of the southern United States. Pine, (genus Pinus), genus of about 115 species of evergreen conifers of the pine family ( Pinaceae), distributed throughout the world but native primarily to northern temperate regions. SpaceNext50 Britannica presents SpaceNext50, From the race to the Moon to space stewardship, we explore a wide range of subjects that feed our curiosity about space!.Learn about the major environmental problems facing our planet and what can be done about them! Saving Earth Britannica Presents Earth’s To-Do List for the 21st Century.Britannica Beyond We’ve created a new place where questions are at the center of learning.100 Women Britannica celebrates the centennial of the Nineteenth Amendment, highlighting suffragists and history-making politicians.COVID-19 Portal While this global health crisis continues to evolve, it can be useful to look to past pandemics to better understand how to respond today. ![]() Student Portal Britannica is the ultimate student resource for key school subjects like history, government, literature, and more.From tech to household and wellness products. This Time in History In these videos, find out what happened this month (or any month!) in history.#WTFact Videos In #WTFact Britannica shares some of the most bizarre facts we can find.Demystified Videos In Demystified, Britannica has all the answers to your burning questions.Britannica Explains In these videos, Britannica explains a variety of topics and answers frequently asked questions.Britannica Classics Check out these retro videos from Encyclopedia Britannica’s archives.
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