Sequoioideae, commonly referred to as redwoods, is a subfamily of coniferous trees within the family Cupressaceae, that range in the northern hemisphere. It includes the largest and tallest trees in the world. The trees in the subfamily are amongst the most notable trees in the world and are common ornamental trees. The subfamily reached its peak of diversity during the early Cenozoic.
The order Pinales in the division Pinophyta, class Pinopsida, comprises all the extant conifers. The distinguishing characteristic is the reproductive structure known as a cone produced by all Pinales. All of the extant conifers, such as Araucaria, cedar, celery-pine, cypress, fir, juniper, kauri, larch, pine, redwood, spruce, and yew, are included here. Some fossil conifers, however, belong to other distinct orders within the division Pinophyta.
Multiple molecular studies indicate this order being paraphyletic with respect to Gnetales, with studies recovering Gnetales as either a sister group to Pinaceae or being more derived than Pinaceae but sister to the rest of the group.
Cupressaceae or the cypress family is a family of conifers. The family includes 27–30 genera (17 monotypic), which include the junipers and redwoods, with about 130–140 species in total. They are monoecious, subdioecious or (rarely) dioecious trees and shrubs up to 116 m (381 ft) tall. The bark of mature trees is commonly orange- to red-brown and of stringy texture, often flaking or peeling in vertical strips, but smooth, scaly or hard and square-cracked in some species. The family reached its peak of diversity during the Mesozoic era.
Cryptomeria (literally "hidden parts") is a monotypic genus of conifer in the cypress family Cupressaceae. It includes only one species, Cryptomeria japonica (syn. Cupressus japonica L.f.). It is considered to be endemic to Japan, where it is known as Sugi (杉). The tree is also called Japanese cedar or Japanese redwood in English. It has been extensively introduced, and cultivated for wood production on the Azores and elsewhere.
Temperate coniferous forest is a terrestrial biome defined by the World Wide Fund for Nature. Temperate coniferous forests are found predominantly in areas with warm summers and cool winters, and vary in their kinds of plant life. In some, needleleaf trees dominate, while others are home primarily to broadleaf evergreen trees or a mix of both tree types. A separate habitat type, the tropical coniferous forests, occurs in more tropical climates.
Temperate coniferous forests are common in the coastal areas of regions that have mild winters and heavy rainfall, or inland in drier climates or montane areas. Many species of trees inhabit these forests including pine, cedar, fir, and redwood. The understory also contains a wide variety of herbaceous and shrub species. Temperate coniferous forests sustain the highest levels of biomass in any terrestrial ecosystem and are notable for trees of massive proportions in temperate rainforest regions.
Sequoia is a genus of redwood coniferous trees in the subfamily Sequoioideae of the family Cupressaceae. The only extant species of the genus is Sequoia sempervirens in the Northern California coastal forests ecoregion of Northern California and Southwestern Oregon in the United States. The two other genera in the subfamily Sequoioideae, Sequoiadendron and Metasequoia, are closely related to Sequoia. It includes the tallest trees, as well as the heaviest, in the world.
Several extinct species have been named from fossils, including Sequoia affinis (Western North America) and Sequoia magnifica (petrified wood from the Yellowstone National Park area).