Ginkgoales are a gymnosperm order containing only one extant species: Ginkgo biloba, the ginkgo tree. It is monotypic, within the class Ginkgoopsida, which itself is monotypic within the division Ginkgophyta. The order includes five families, of which only Ginkgoaceae remains extant.
Cycads are seed plants that typically have a stout and woody (ligneous) trunk with a crown of large, hard, stiff, evergreen and (usually) pinnate leaves. The species are dioecious, that is, individual plants of a species are either male or female. Cycads vary in size from having trunks only a few centimeters to several meters tall. They typically grow very slowly and live very long. Because of their superficial resemblance, they are sometimes mistaken for palms or ferns, but they are not closely related to either group.
Araucariaceae – also known as araucarians – is a family of coniferous trees. The family achieved its maximum diversity during the Jurassic and Cretaceous periods, when it was distributed almost worldwide. Most of the Araucariaceae in the Northern Hemisphere vanished in the Cretaceous–Paleogene extinction event, and they are now largely confined to the Southern Hemisphere, except for a few species of Agathis in Southeast Asia.
The gymnosperms are a group of seed-producing plants that includes conifers, cycads, Ginkgo, and gnetophytes, forming the clade Gymnospermae. The term gymnosperm comes from the composite word in Greek: γυμνόσπερμος, literally meaning 'naked seeds'. The name is based on the unenclosed condition of their seeds. The non-encased condition of their seeds contrasts with the seeds and ovules of flowering plants (angiosperms), which are enclosed within an ovary. Gymnosperm seeds develop either on the surface of scales or leaves, which are often modified to form cones, or on their own as in yew, Torreya, Ginkgo. Gymnosperm lifecycles involve alternation of generations. They have a dominant diploid sporophyte phase and a reduced haploid gametophyte phase which is dependent on the sporophytic phase. The term "gymnosperm" is often used in paleobotany to refer to all non-angiosperm seed plants. In that case, to specify the modern monophyletic group of gymnosperms, the term Acrogymnospermae is sometimes used.
Cupressaceae is a conifer family, the cypress family, with worldwide distribution. The family includes 27–30 genera, 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.
Chamaecyparis, common names cypress or false cypress, is a genus of conifers in the cypress family Cupressaceae, native to eastern Asia and to the western and eastern margins of the United States. The name is derived from the Greek khamai (χαμαί), meaning "on the earth", and kuparissos (κυπάρισσος) for "cypress".
Sciadopitys verticillata, the kōyamaki or Japanese umbrella-pine, is a unique conifer endemic to Japan. It is the sole living member of the family Sciadopityaceae and genus Sciadopitys, a living fossil with no close relatives. The oldest fossils of Sciadopitys are from the Late Cretaceous of Japan, and the genus was widespread in Laurasia during most of the Cenozoic, especially in Europe until the Pliocene.
Podocarpaceae is a large family of mainly Southern Hemisphere conifers, known in English as podocarps, comprising about 156 species of evergreen trees and shrubs. It contains 19 genera if Phyllocladus is included and Manoao and Sundacarpus are recognized.
Taiwania, with the single living species Taiwania cryptomerioides, is a large coniferous tree in the cypress family Cupressaceae.
Cunninghamia is a genus of one or two living species of evergreen coniferous trees in the cypress family Cupressaceae. They are native to China, northern Vietnam and Laos, and perhaps also Cambodia. They may reach 50 m (160 ft) in height. In vernacular use, it is most often known as Cunninghamia, but is also sometimes called "China-fir". The genus name Cunninghamia honours Dr. James Cunningham, a British doctor who introduced this species into cultivation in 1702 and botanist Allan Cunningham.
Xanthocyparis is a genus of cypresses in the family Cupressaceae. As of August 2021, it has only one species, Xanthocyparis vietnamensis, native to Vietnam and southeast China. It is commonly known as the Vietnamese golden cypress. The Nootka cypress, Cupressus nootkatensis or Callitropsis nootkatensis, was also placed in the genus, but this has been rejected.
Cycas is a genus of cycad, and the only genus in the family Cycadaceae. About 113 species are accepted, which are native to the Asia-Pacific, East Africa and Madagascar. Cycas circinalis, a species endemic to India, was the first cycad species to be described in western literature, and is the type species of the genus. The best-known Cycas species is Cycas revoluta.
Athrotaxis is a genus of two to three species of conifers in the cypress family, Cupressaceae. The genus is endemic to western Tasmania, where they grow in high altitude temperate rainforests.
Macrozamia is a genus of around forty species of cycads, family Zamiaceae, all of which are endemic to Australia. Many parts of the plant have been utilised for food and material, most of which is toxic if not processed correctly.
Encephalartos is a genus of cycad native to Africa. Several species of Encephalartos are commonly referred to as bread trees, bread palms or kaffir bread, since a bread-like starchy food can be prepared from the centre of the stem. The genus name is derived from the Greek words en (within), kephalē (head), and artos (bread), referring to the use of the pith to make food. They are, in evolutionary terms, some of the most primitive living gymnosperms.
Cephalotaxus, commonly called plum yew or cowtail pine, is a genus of conifers comprising 11 species, either considered the only member of the family Cephalotaxaceae, or in the Taxaceae when that family is considered in a broad sense. The genus is endemic to eastern Asia, though fossil evidence shows it had a wider Northern Hemisphere distribution in the past. The species are evergreen shrubs and small trees reaching 1.0–10 metres (3–33 ft) tall.
Dioon is a genus of cycads in the family Zamiaceae. It is native to Mexico and Central America. Their habitats include tropical forests, pine-oak forest, and dry hillsides, canyons and coastal dunes.
Lepidozamia peroffskyana is a palm-like cycad in the family Zamiaceae. It is endemic to eastern Australia. The species is named after Count Peroffsky (1794-1857), benefactor of the St. Petersburg Botanical Garden.
Ginkgo is a genus of non-flowering seed plants. The scientific name is also used as the English name. The order to which it belongs, Ginkgoales, first appeared in the Permian, 270 million years ago, and Ginkgo is now the only living genus within the order. The rate of evolution within the genus has been slow, and almost all its species had become extinct by the end of the Pliocene. The sole surviving species, Ginkgo biloba is only found in the wild in China, but is cultivated around the world. The relationships between ginkgos and other groups of plants are not fully resolved.
Sequoioideae, popularly known as redwoods, is a subfamily of coniferous trees within the family Cupressaceae. It includes the largest and tallest trees in the world.
