Welwitschiaceae

	Welwitschiaceae Welwitschiaceae is a family of plants of the order Gnetales with one living species, ''Welwitschia mirabilis'', found in southwestern Africa. Three fossil genera have been recovered from the Crato Formation – late Aptian (Lower Cretaceous) strata located in the Araripe Basin in northeastern Brazil, with one of these also being known from the early Late Cretaceous ( Cenomanian-Turonian) Akrabou Formation of Morocco. Taxonomy German naturalist Friedrich Markgraf coined the name Welwitschiaceae in 1926, which appeared in ''Die Natürlichen Pflanzenfamilien''. Most recent systems place the Welwitschiaceae in the gymnosperm order Gnetales. This order is most closely related to the order Pinales, which includes Araucariaceae - Araucarians, Cupressaceae - Cypress Family, Pinaceae - Pine Family, Podocarpaceae - Podocarps, Sciadopityaceae - Koyamaki Family (the sole membeSciadopitys verticillata - Koyamaki, Taxaceae - Yew Family. Genetic analyses indicate that the Gnetales arose fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Welwitschia Mirabilis ''Welwitschia'' is a monotypic gymnosperm genus, comprising solely the distinctive ''Welwitschia mirabilis'', endemic to the Namib desert within Namibia and Angola. ''Welwitschia'' is the only living genus of the family Welwitschiaceae and order Welwitschiales in the division Gnetophyta, and is one of three living genera in Gnetophyta, alongside ''Gnetum'' and ''Ephedra''. Informal sources commonly refer to the plant as a "living fossil". Naming ''Welwitschia'' is named after the Austrian botanist and doctor Friedrich Welwitsch, who described the plant in Angola in 1859. Welwitsch was so overwhelmed by the plant that he, "could do nothing but kneel down ..and gaze at it, half in fear lest a touch should prove it a figment of the imagination." Joseph Dalton Hooker of the Linnean Society of London, using Welwitsch's description and collected material along with material from the artist Thomas Baines who had independently recorded the plant in Namibia, described the species. Wel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Welwitschia ''Welwitschia'' is a monotypic gymnosperm genus, comprising solely the distinctive ''Welwitschia mirabilis'', endemic to the Namib desert within Namibia and Angola. ''Welwitschia'' is the only living genus of the family Welwitschiaceae and order Welwitschiales in the division Gnetophyta, and is one of three living genera in Gnetophyta, alongside ''Gnetum'' and ''Ephedra''. Informal sources commonly refer to the plant as a "living fossil". Naming ''Welwitschia'' is named after the Austrian botanist and doctor Friedrich Welwitsch, who described the plant in Angola in 1859. Welwitsch was so overwhelmed by the plant that he, "could do nothing but kneel down ..and gaze at it, half in fear lest a touch should prove it a figment of the imagination." Joseph Dalton Hooker of the Linnean Society of London, using Welwitsch's description and collected material along with material from the artist Thomas Baines who had independently recorded the plant in Namibia, described the species. Wel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Gnetales Gnetophyta () is a division of plants (alternatively considered the subclass Gnetidae or order Gnetales), grouped within the gymnosperms (which also includes conifers, cycads, and ginkgos), that consists of some 70 species across the three relict genera: ''Gnetum'' (family Gnetaceae), ''Welwitschia'' (family Welwitschiaceae), and ''Ephedra'' (family Ephedraceae). Fossilized pollen attributed to a close relative of ''Ephedra'' has been dated as far back as the Early Cretaceous. Though diverse in the Early Cretaceous, only three families, each containing a single genus, are still alive today. The primary difference between gnetophytes and other gymnosperms is the presence of vessel elements, a system of conduits that transport water within the plant, similar to those found in flowering plants. Because of this, gnetophytes were once thought to be the closest gymnosperm relatives to flowering plants, but more recent molecular studies have brought this hypothesis into question. Thoug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Gymnosperm The gymnosperms ( lit. revealed seeds) 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 el, γυμνόσπερμος ( el, γυμνός, translit=gymnos, lit=naked, label=none and el, σπέρμα, translit=sperma, lit=seed, label=none), literally meaning 'naked seeds'. The name is based on the unenclosed condition of their seeds (called ovules in their unfertilized state). 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 solitary 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Teodoro Caruel Théodore (Teodoro) Caruel (27 June 1830 – 4 December 1898) was an Italian botanist of French-English parentage who specialized in flora of Tuscany. He was born in Chandernagor, a French colonial enclave north of Calcutta, where his father served as a French official. At the age of 15, he moved with his family to Florence, where soon afterwards, he developed an interest in natural sciences, in particular, flora native to Tuscany. In 1858 he began work as an assistant to Filippo Parlatore, and within a few years was given the title of coadjutor. With Parlatore, he conducted research at the ''Orto Botanico di Firenze'' (botanic museum of Florence) and worked on the development of the Florence herbarium.Google Books Journal of Botany, British and Foreign, Volume 37 edited by Berthold Seemann [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Welwitschiella ''Welwitschiella'' is a genus of African plants in the aster tribe within the daisy family.Hoffmann, Karl August Otto. 1894. Die Natürlichen Pflanzenfamilien 4(5): 390-391 in German ;Species There is only one known species, ''Welwitschiella neriifolia'', native to Angola , Zaïre , and Zambia Zambia (), officially the Republic of Zambia, is a la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Kaokoveld The Kaokoveld Desert is a coastal desert of northern Namibia and southern Angola. Setting The Kaokoveld Desert occupies a coastal strip covering , from 13° to 21°S and is bounded by the Atlantic Ocean to the west, the Namibian savanna woodlands to the east, and the Namib Desert to the south. It includes the Moçâmedes Desert of southern Angola. The Kaokoveld is a harsh desert of drifting sandunes and rocky mountains. It receives most of its rainfall during the summer, which distinguishes it from the adjacent Namib Desert to the south, which receives most of its rain during the winter. The Kunene River is the only permanent watercourse but many dry riverbeds (including the Hoanib, Hoarusib and Khumib Rivers) carry moisture through the desert and are home to animals including elephants, black rhinos, and giraffe. Other than those the area is ancient desert sand, moistened by occasional coastal fog. Flora The Kaokoveld is home to ''Welwitschia mirabilis'', a plant that has n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Early Cretaceous The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Proposals for the exact age of the Barremian-Aptian boundary ranged from 126 to 117 Ma until recently (as of 2019), but based on drillholes in Svalbard the defining early Aptian Oceanic Anoxic Event 1a (OAE1a) was carbon isotope dated to 123.1±0.3 Ma, limiting the possible range for the boundary to c. 122–121 Ma. There is a possible link between this anoxic event and a series of Early Cretaceous large igneous provinces (LIP). The Ontong Java-Manihiki-Hikurangi large igneous province, emplaced in the South Pacific at c. 120 Ma, is by far the largest LIP in Earth's history. The Ontong Java Plateau today covers an area of 1,860,000 km2. In the Indian Ocean another LIP began to form at c. 120 Ma, the Kerguelen P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Cotyledon A cotyledon (; ; ; , gen. (), ) is a significant part of the embryo within the seed of a plant, and is defined as "the embryonic leaf in seed-bearing plants, one or more of which are the first to appear from a germinating seed." The number of cotyledons present is one characteristic used by botanists to classify the flowering plants (angiosperms). Species with one cotyledon are called monocotyledonous ("monocots"). Plants with two embryonic leaves are termed dicotyledonous ("dicots"). In the case of dicot seedlings whose cotyledons are photosynthetic, the cotyledons are functionally similar to leaves. However, true leaves and cotyledons are developmentally distinct. Cotyledons are formed during embryogenesis, along with the root and shoot meristems, and are therefore present in the seed prior to germination. True leaves, however, are formed post-embryonically (i.e. after germination) from the shoot apical meristem, which is responsible for generating subsequent aerial por ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]