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.
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.
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".
The genus Bowenia includes two living and two fossil species of cycads in the family Stangeriaceae, sometimes placed in their own family Boweniaceae. They are entirely restricted to Australia. The two living species occur in Queensland. B. spectabilis grows in warm, wet, tropical rainforests, on protected slopes and near streams, primarily in the lowlands of the Wet Tropics Bioregion. However, it has a local form with serrate pinna margins that grows in rainforest, Acacia-dominated transition forest, and also Casuarina-dominated sclerophyll forest on the Atherton Tableland, where it is subject to periodic bushfire. B. serrulata grows in sclerophyll forest and transition forest close to the Tropic of Capricorn.
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.
The Zamiaceae are a family of cycads that are superficially palm or fern-like. They are divided into two subfamilies with eight genera and about 150 species in the tropical and subtropical regions of Africa, Australia and North and South America.
Zamia is a genus of cycad of the family Zamiaceae, native to North America from the United States throughout the West Indies, Central America, and South America as far south as Bolivia. The genus is considered to be the most ecologically and morphologically diverse cycads, and is estimated to have originated about 68.3 million years ago.
Torreya is a genus of conifers comprising six or seven species placed in the family Taxaceae, though sometimes formerly placed in Cephalotaxaceae. Four species are native to eastern Asia; the other two are native to North America. They are small to medium-sized evergreen trees reaching 5–20 m, rarely 25 m, tall. Common names include nutmeg yew.
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.
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 is a genus of two species of cycad, both endemic to Australia. They are native to rainforest climates in eastern Queensland and eastern New South Wales. They have a diploid chromosome number of 2n = 18.
Ceratozamia sabatoi is a species of plant in the family Zamiaceae. It is endemic to Mexico, where it occurs in the states of Hidalgo and Querétaro. It is known from only two localities, one of which is degraded by agriculture and grazing.
Ceratozamia whitelockiana is a species of plant in the family Zamiaceae. It is endemic to Mexico, where it is known only from Metates and Chiapan in Oaxaca state. Only two subpopulations have been found, with a total population of about 2200 individuals. The habitat is threatened by conversion to plantations using slash-and-burn techniques.
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.
This article records new taxa of fossil plants that are scheduled to be described during the year 2019, as well as other significant discoveries and events related to paleobotany that are scheduled to occur in the year 2019.
Concavistylon is an extinct genus of flowering plant in the family Trochodendraceae comprising a single species Concavistylon kvacekii. The genus is known from fossils found in Middle Miocene deposits of central Oregon. A second species "Concavistylon" wehrii was originally placed in Concavistylon, but subsequently moved to a new genus Paraconcavistylon in 2020.
This article records new taxa of fossil plants that are scheduled to be described during the year 2020, as well as other significant discoveries and events related to paleobotany that are scheduled to occur in the year 2020.
Eostangeria is a morphogenus of fossil foliage belonging to the Cycadales.
