The Pinaceae, or pine family, is a large family of conifers, including many of the well-known conifers of commercial importance such as cedars, firs, hemlocks, larches, pines, and spruces. The family is included in the order Pinales, formerly known as Coniferales. Pinaceae have distinctive cones with woody scales bearing typically two ovules, and are supported as monophyletic by both morphological trait and genetic analysis. They are the largest extant conifer family in species diversity, with between 220 and 250 species (depending on taxonomic opinion) in 11 genera, and the second-largest (after Cupressaceae) in geographical range, found in most of the Northern Hemisphere, with the majority of the species in temperate climates, but ranging from subarctic to tropical. The family often forms the dominant component of boreal, coastal, and montane forests. One species, Pinus merkusii, grows just south of the equator in Southeast Asia. Major centres of diversity are found in the mountains of southwest China, Mexico, central Japan, and California.
Description
The members of the family Pinaceae are trees (rarely shrubs) growing from 2 to 100 metres (7 to 300 feet) tall, mostly evergreen (except the deciduous Larix and Pseudolarix), resinous, monoecious, with subopposite or whorled branches, and spirally arranged, linear (needle-like) leaves. The embryos of Pinaceae have three to 24 cotyledons.
The female cones are large and usually woody, 2–60 centimetres (1–24 inches) long, with numerous spirally arranged scales, and two winged seeds on each scale. The male cones are small,
Boreal conifers have multiple adaptations to survive winters, including the tree's conical shape to shed snow, strong tracheid vessels to tolerate ice pressure, and a waxy covering on the needle leaves to minimise water loss.
Features of Pinus sylvestris
Cultivated pine forest in Western Ghats, India
Evolution
The Pinaceae diverged from other conifer groups during the...
