in the south.
The Madrean Region is characterized a very distinct
florawith at least three endemic families ( Fouquieriaceae, Simmondsiaceae, and Setchellanthaceae). Crossosomataceae, Garryaceae, Lennoaceae, Limnanthaceaeand Stegnospermataceaehave their principal development here; for Onagraceae, Polemoniaceaeand Hydrophyllaceaeit is the major center of diversity. More than 250 genera and probably more than half of the speciesof the region are endemic to it according to Takhtajan. The region is subdivided into four floristic provinces: the Great Basin Province, Californian Province, Sonoran Province and Mexican Highlands Province.
The Great Basin Province includes most of the
Great Basin. It shares much of its flora with the neighboring provinces and has but few endemic genera. Speciesendemism is also moderate (about 25%), but is much more considerable in such genera as " Astragalus", " Eriogonum", " Penstemon", " Cymopterus", " Lomatium", " Cryptantha", " Chrysothamnus", " Erigeron", " Phacelia", " Castilleja", and " Gilia". The vegetation is dominated by " Artemisia" species and Chenopodiaceaein the central part of the province.
Californian Provinceoccupies Central and Southern Californiafrom the seashore to the foothills of the Cascade Rangeand Sierra Madre, as well as northern parts of Baja Californiaof Mexico. It possesses the most diverse flora within the floristic region. About half of the species are endemic. More than 50 genera (e.g. " Adenostoma", " Bergerocactus", " Carpenteria", " Cneoridium", " Dendromecon", " Fremontodendron", " Jepsonia", " Lyonothamnus", " Neostapfia", " Odontostomum", " Ornithostaphylos", " Pickeringia", " Romneya") are endemic or near-endemic as well. " Arctostaphylos", Brodiaeinae, " Calochortus", " Caulanthus", " Streptanthus", " Ceanothus", " Cryptantha", " Downingia", " Dudleya", Eritrichieae, Eriogonoideae, Gileae, Hydrophyllaceae, Limnanthaceae, " Lotus", Madiinae, " Mimulus", Onagreae, Epilobieae, Orcuttieae, Eschscholzioideae, Platystemonoideae, " Astragalus" and " Cupressus" have a principal center of diversity within the province. The flora of the Californian Province is partially shared with the spatially distant Chile-Patagonian Region of the Antarctic Kingdomand to a lesser extent Mediterranean Regionof the Holarctic Kingdom. The vegetation of the Californian Province is varied. Wetter northern parts of the Californian Province ( Northern Californiaand Oregon) as defined by Peter Ravenand D.I. Axelrod, as well as by Conservation International, fall under the Rocky Mountain Regionin Takhtajan and Thorne's system and don't make parts of the Madrean Region.
The Sonoran Province comprises arid areas in the southwestern U.S. and northwestern Mexico from
Californiaand Baja Californiato Texasand Tamaulipas, including the Mojave (characterized by " Yucca brevifolia", Joshua Tree), Sonora and Chihuahua Deserts. The vegetation is dominated by " Yucca", Cactaceaespecies (" Opuntia" spp. and other), as well as by " Larrea tridentata" (Creosote bush).
*Thorne, Robert F. [http://hua.huh.harvard.edu/FNA/Volume/V01/Chapter06.shtml Phytogeography of North America North of Mexico] . "
Flora of North America", Vol. 1, Ch. 6.
Wikimedia Foundation. 2010.
Look at other dictionaries:
Madrean Sky Islands — The Madrean sky islands are enclaves of Madrean pine oak woodlands, found at higher elevations in a complex of small mountain ranges in southern Arizona and New Mexico and northern Mexico. The sky islands are surrounded at lower elevations by the … Wikipedia
Madrean Pine-Oak Woodlands — Geschlossener Kiefernwald an der Straße von San Isidro Llano Grande und San Miguel Cajonos, in der Sierra Madre de Oaxaca … Deutsch Wikipedia
Bois de pins et chênes de Madrean — Bois de pin de la Sierra Madre de Oaxaca Les Bois de pins et chênes de la Sierra Madre Occidental forment un ensemble de forêts subtropicales situées au Mexique considéré comme un hotspot de biodiversité par Conservation International … Wikipédia en Français
Rocky Mountain Region — The Rocky Mountain Region is a floristic region within the Holarctic Kingdom in western North America (Canada and the United States) delineated by Armen Takhtajan and Robert F. Thorne. It spans from Kodiak Island of Alaska approximately to the… … Wikipedia
North American Atlantic Region — The Blue Ridge, heartland of the region … Wikipedia
Eastern Asiatic Region — A forest in Sichuan Bamboo forest in Lushan, China … Wikipedia
Circumboreal Region — Floristic regions in Europe according to Wolfgang Frey and Rainer Lösch … Wikipedia
Boreal Kingdom — Good noted that the plant species of temperate North America and Eurasia were very closely related, despite their separation by the Atlantic Ocean and the Bering Strait.Millions of years ago, before the opening of the Atlantic Ocean, North… … Wikipedia
Reino floral — Saltar a navegación, búsqueda Mapa en el que se muestran los seis reinos florales Los reinos florales son las grandes zonas en las que se divide la Tierra por presentar una vegetación común. En biogeografía (y más especificamente, en… … Wikipedia Español
Phytochorion — A Phytochorion, in phytogeography, is a geographic area with a relatively uniform composition of plant species. Adjacent phtyochoria do not usually have a sharp boundary, but rather a soft one, a transitional area in which many species from both… … Wikipedia