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Amentotaxus
''Amentotaxus'' is a genus of conifers (catkin-yews) comprising five species, treated in either the Cephalotaxaceae, or in the Taxaceae when that family is considered in a broad sense. The genus is endemic to subtropical Southeast Asia, from Taiwan west across southern China to Assam in the eastern Himalaya, and south to Vietnam. The species are evergreen shrubs and small trees reaching 2–15 m tall. The leaves are spirally arranged on the shoots, but twisted at the base to lie in two flat ranks (except on erect leading shoots); they are linear-lanceolate, 4–12 cm long and 6–10 mm broad, soft in texture, with a blunt tip, green above, and with two conspicuous white stomatal bands below. They differ from the related genus ''Cephalotaxus'' in the broader leaves, and from ''Torreya'' by the blunt, not spine-tipped leaves. The species can be either monoecious or dioecious; when monoecious, the male and female cones are often on different branches. The male (pollen) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amentotaxus Argotaenia
''Amentotaxus argotaenia'', the catkin yew, is a species of conifer in the family Taxaceae. It is a shrub or a small tree up to tall. ''Amentotaxus argotaenia'' var. ''brevifolia'' has been described from southern Guizhou and listed separately by IUCN. ''Amentotaxus formosana'' was previously recognised as a variant of ''A. argotaenia''. Distribution In mainland China, the species is found in Fujian, southern Gansu, Guangdong, Guangxi, Guizhou, western Hubei, Hunan, Jiangsu, northwestern Jiangxi, central and southeastern Sichuan, southeastern Tibet and southern Zhejiang. It also occurs in Taiwan. In Hong Kong, it is distributed in Ma On Shan, Tai Mo Shan, Mount Parker, Sunset Peak, Lantau Peak, and Sai Kung Peninsula. In the Shing Mun Arboretum, a living specimen is displayed.''Amentotax ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amentotaxus Formosana (Jardin Des Plantes De Paris)
''Amentotaxus formosana'', the Taiwan catkin yew, is a species of conifer in the family Taxaceae. It is a small tree to tall, with a slender trunk. It was previously recognised as a variant of '' Amentotaxus argotaenia''. ''Amentotaxus formosana'' is found only in Taiwan where it only occurs in four localities of cloud forest in the Hengchun Peninsula, in the extreme south of the island. IUCN considers ''A. formosana'' as critically endangered because of its populations are small and threatened by habitat loss Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby .... The populations are characterized by very low levels of genetic diversity. The wood is used for making furniture and handicrafts, etc., and the species is sometimes cultivated as an ornamental tree. References f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amentotaxus Formosana
''Amentotaxus formosana'', the Taiwan catkin yew, is a species of conifer in the family Taxaceae. It is a small tree to tall, with a slender trunk. It was previously recognised as a variant of '' Amentotaxus argotaenia''. ''Amentotaxus formosana'' is found only in Taiwan where it only occurs in four localities of cloud forest in the Hengchun Peninsula, in the extreme south of the island. IUCN considers ''A. formosana'' as critically endangered because of its populations are small and threatened by habitat loss Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby .... The populations are characterized by very low levels of genetic diversity. The wood is used for making furniture and handicrafts, etc., and the species is sometimes cultivated as an ornamental tree. References f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxaceae
Taxaceae (), commonly called the yew family, is a coniferous family which includes six extant and two extinct genera, and about 30 species of plants, or in older interpretations three genera and 7 to 12 species. Description They are many-branched, small trees and shrubs. The leaves are evergreen, spirally arranged, often twisted at the base to appear 2-ranked. They are linear to lanceolate, and have pale green or white stomatal bands on the undersides. The plants are dioecious, or rarely monoecious. The catkin like male cones are long, and shed pollen in the early spring. They are sometimes externally only slightly differentiated from the branches. The fertile bracts have 2-8 pollen sacs. The female 'cones' are highly reduced. Only the upper or uppermost bracts are fertile and bear one or rarely two seeds. The ovule usually exceeds the scale, although ovules are sometimes rarely enclosed by it. They may be found on the ends of branches or on the branches. They may grow sin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amentotaxus Yunnanensis
''Amentotaxus yunnanensis'', the Yunnan catkin yew, is a species of conifer in the yew family, Taxaceae. It is native to Laos, Vietnam, and Guizhou and Yunnan Yunnan , () is a landlocked province in the southwest of the People's Republic of China. The province spans approximately and has a population of 48.3 million (as of 2018). The capital of the province is Kunming. The province borders the C ... in China. It is a medium-sized tree to tall. Remaining populations are small and threatened by logging. References yunnanensis Trees of Laos Trees of China Trees of Vietnam Vulnerable plants Taxonomy articles created by Polbot Plants described in 1952 {{conifer-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amentotaxus Poilanei
''Amentotaxus poilanei'' is a species of conifer in the yew family, Taxaceae. It is endemic to Vietnam Vietnam or Viet Nam ( vi, Việt Nam, ), officially the Socialist Republic of Vietnam,., group="n" is a country in Southeast Asia, at the eastern edge of mainland Southeast Asia, with an area of and population of 96 million, making i .... Its common name is Poilane's catkin yew. References poilanei Vulnerable plants Endemic flora of Vietnam Taxonomy articles created by Polbot {{conifer-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amentotaxus Assamica
''Amentotaxus assamica'' is a species of conifer in the family Taxaceae. It is found only in India. It is threatened by habitat loss Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby .... References assamica Taxonomy articles created by Polbot Plants described in 1985 {{conifer-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jurassic
The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of the Mesozoic, Mesozoic Era and is named after the Jura Mountains, where limestone strata from the period were first identified. The start of the Jurassic was marked by the major Triassic–Jurassic extinction event, associated with the eruption of the Central Atlantic magmatic province, Central Atlantic Magmatic Province. The beginning of the Toarcian Stage started around 183 million years ago and is marked by an extinction event associated with widespread Anoxic event, oceanic anoxia, ocean acidification, and elevated temperatures likely caused by the eruption of the Karoo-Ferrar, Karoo-Ferrar large igneous provinces. The end of the Jurassic, however, has no clear boundary with the Cretaceous and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pollen
Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametophytes during the process of their movement from the stamens to the pistil of flowering plants, or from the male cone to the female cone of gymnosperms. If pollen lands on a compatible pistil or female cone, it germinates, producing a pollen tube that transfers the sperm to the ovule containing the female gametophyte. Individual pollen grains are small enough to require magnification to see detail. The study of pollen is called palynology and is highly useful in paleoecology, paleontology, archaeology, and forensics. Pollen in plants is used for transferring haploid male genetic material from the anther of a single flower to the stigma of another in cross-pollination. In a case of self-pollination, this process takes place from the anth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Torreya
''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. The genus is one example of the Arcto-Tertiary Geoflora in paleoecology. The pattern of highly disjunct distribution of geographic ranges of the species within such a genus spans temperate plant zones of continents in the Northern Hemisphere. This geographic pattern is attributed to genus origins in much warmer times of the Tertiary Period, when zones of temperate climate were found in poleward latitudes whereby land connections facilitated range expansions and migrations of plants between Asia and North America and sometimes between Europe and North America. The leaves are spirally arranged on the shoots, but twisted at the base ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant Sexuality
Plant reproductive morphology is the study of the physical form and structure (the Plant morphology, morphology) of those parts of plants directly or indirectly concerned with sexual reproduction. Among all living organisms, flowers, which are the reproductive structures of flowering plant, angiosperms, are the most varied physically and show a correspondingly great diversity in methods of reproduction. Plants that are not flowering plants (green algae, mosses, Marchantiophyta, liverworts, hornworts, ferns and gymnosperms such as conifers) also have complex interplays between morphological adaptation and environmental factors in their sexual reproduction. The breeding system, or how the sperm from one plant fertilizes the ovum of another, depends on the reproductive morphology, and is the single most important determinant of the genetic structure of nonclonal plant populations. Christian Konrad Sprengel (1793) studied the reproduction of flowering plants and for the first time it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conifer Cone
A conifer cone (in formal botany, botanical usage: strobilus, plural strobili) is a seed-bearing organ on gymnosperm plants. It is usually woody, ovoid to globular, including scales and bracts arranged around a central axis, especially in conifers and cycads. The cone of Pinophyta (conifer clade) contains the plant sexuality, reproductive structures. The woody cone is the female cone, which produces seeds. The male cone, which produces pollen, is usually herbaceous plant, herbaceous and much less conspicuous even at full maturity. The name "cone" derives from Greek ''konos'' (pine cone), which also gave name to the cone (geometry), geometric cone. The individual plates of a cone are known as ''scales''. The ''umbo'' of a conifer cone refers to the first year's growth of a seed scale on the cone, showing up as a protuberance at the end of the two-year-old scale. The male cone (microstrobilus or pollen cone) is structurally similar across all conifers, differing only in small wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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