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Madrean Pine-Oak Woodlands Hotspot 2005 Print
The Madrean Region (named after the Sierra Madre Occidental) is a floristic region within the Holarctic Kingdom in North America, as delineated by Armen Takhtajan and Robert F. Thorne. It occupies arid or semiarid areas in the southwestern United States and northwestern Mexico and is bordered by the Rocky Mountain Region and North American Atlantic Region of the Holarctic Kingdom in the north and in the east, Caribbean Region of the Neotropical Kingdom in the south. The Madrean Region is characterized by a very distinct flora with at least three endemic families ( Fouquieriaceae, Simmondsiaceae, and Setchellanthaceae). Crossosomataceae, Garryaceae, Lennoaceae, Limnanthaceae and Stegnospermataceae have their principal development here; for Onagraceae, Polemoniaceae and Hydrophyllaceae it is the major center of diversity. More than 250 genera and probably more than half of the species of the region are endemic to it according to Takhtajan. Floristic provinces The region is subdi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemism
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, the Cape sugarbird is found exclusively in southwestern South Africa and is therefore said to be ''endemic'' to that particular part of the world. An endemic species can be also be referred to as an ''endemism'' or in scientific literature as an ''endemite''. For example '' Cytisus aeolicus'' is an endemite of the Italian flora. '' Adzharia renschi'' was once believed to be an endemite of the Caucasus, but it was later discovered to be a non-indigenous species from South America belonging to a different genus. The extreme opposite of an endemic species is one with a cosmopolitan distribution, having a global or widespread range. A rare alternative term for a species that is endemic is "precinctive", which applies to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus comes above species and below family (taxonomy), family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. ''Panthera leo'' (lion) and ''Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomy (biology), taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polemoniaceae
The Polemoniaceae (Jacob's-ladder or phlox family) are a family of flowering plants consisting of about 25 genera with 270–400 species of annuals and perennials native to the Northern Hemisphere and South America, with the center of diversity in western North America. Only one genus (''Polemonium'') is found in Europe, and two (''Phlox'' and ''Polemonium'') in Asia, where they are confined to cool temperate to arctic regions; both genera also occur more widely in North America, suggesting relatively recent colonization of the Old World from North America. The family can be distinguished from most other eudicot families by the ovary made up of three fused carpels (usually with three chambers, but with one chamber in some species). The members of the family have five sepals, five petals fused, and five stamens that alternate with the lobes of the corolla. For decades, most sources used a classification of the family published by Grant in 1959, but new evidence, including mol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Onagraceae
The Onagraceae are a family of flowering plants known as the willowherb family or evening primrose family. They include about 650 species of herbs, shrubs, and treesOnagraceae. Flora of China. in 17 genera. The family is widespread, occurring on every continent from boreal to regions. The family includes a number of popular plants, including evening primroses ('''') and [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stegnospermataceae
''Stegnosperma'' is a genus of flowering plants, consisting of three species of woody plants, native to the Caribbean, Central America, and the Sonoran Desert. These are shrubs or lianas, with anomalous secondary thickening in mature stems, by successive cambia. Leaves are alternate, entire, 2–5 cm in length, tapering at both ends. Flowers are small (5–8 mm), five-merous, with white petal-like sepals, and a superior ovary. They are arranged in short racemes, usually no more than 10 cm long, shorter in ''S. watsonii''. The fruit is a capsule 5–8 mm in diameter: it contains small (2–3 mm) black seeds with a conspicuous reddish aril. The genus has commonly been treated as belonging to the family Phytolaccaceae, but the APG system and APG II system, of 2003, regard it as the sole genus of its own family, the Stegnospermataceae and assign it to the order Caryophyllales in the clade core eudicots Turner et al. suggest that ''S. halimifolium'' Ben ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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