|
Dioon Edule
''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. Description Dioons are dioecious, palmlike shrubs with cylindrical stems, usually with many leaves. The species in the genus ''Dioon'' are perennial, evergreen cycads with cylindrical stem axis is partially in the ground. The plant is thickened and made of soft wood, rarely having above ground branches. Leaf bases are persistent or shedding to leave smooth bark. The leaves are pinnate, spirally arranged, interspersed with cataphylls, with leaflets not articulated and lacking a midrib. The lower leaflets are often reduced to spines. The sporophylls are not in vertical rows in cones, and the megasporophyll apices are broadly flattened, upturned, and overlapping. Species in the genus Dioon have 2n = 18 chromosomes. The largest species is '' D. spinolosum'', which are over 16 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cataphyll
In plant morphology, a cataphyll (sometimes also called a ''cataphyllum'' or cataphyll leafJackson, Benjamin, Daydon; A Glossary of Botanic Terms with their Derivation and Accent; Published by Gerald Duckworth & Co. London, 4th ed 1928) is a reduced, small leaf. Many plants have both "true leaves" (''euphylls''), which perform most of the photosynthesis, and cataphylls, which are modified to perform other functions. Cataphylls include bracts, bracteoles and bud scales, as well as any small leaves that resemble Scale (anatomy), scales, known as wiktionary:scale_leaf, scale leaves. The functions of cataphylls, such as bud scales, may be short-lived, and they are often shed after their function is fulfilled. Etymology Cataphyll comes from the Ancient Greek ("kata"), meaning "down", and ("phyllon"), meaning "leaf". Forms In some cases, cataphylls perform a wikt:transient, transient function, after which they die and may shed. Those that shed early are said to be Glossary of botani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleocene
The Paleocene ( ), or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name is a combination of the Ancient Greek ''palaiós'' meaning "old" and the Eocene Epoch (which succeeds the Paleocene), translating to "the old part of the Eocene". The epoch is bracketed by two major events in Earth's history. The K–Pg extinction event, brought on by an asteroid impact (Chicxulub impact) and possibly volcanism (Deccan Traps), marked the beginning of the Paleocene and killed off 75% of species, most famously the non-avian dinosaurs. The end of the epoch was marked by the Paleocene–Eocene Thermal Maximum (PETM), which was a major climatic event wherein about 2,500–4,500 gigatons of carbon were released into the atmosphere and ocean systems, causing a spike in global temperatures and ocean acidification. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cenozoic
The Cenozoic Era ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterized by the dominance of mammals, insects, birds and angiosperms (flowering plants). It is the latest of three geological eras of the Phanerozoic Eon, preceded by the Mesozoic and Paleozoic. The Cenozoic started with the Cretaceous–Paleogene extinction event, when many species, including the non-avian dinosaurs, became extinct in an event attributed by most experts to the impact of a large asteroid or other celestial body, the Chicxulub impactor. The Cenozoic is also known as the Age of Mammals because the terrestrial animals that dominated both hemispheres were mammalsthe eutherians ( placentals) in the Northern Hemisphere and the metatherians (marsupials, now mainly restricted to Australia and to some extent South America) in the Southern Hemisphere. The extinction of many groups allowed mammals and birds to greatly diversify so that large m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orography
Orography is the study of the topographic relief of mountains, and can more broadly include hills, and any part of a region's elevated terrain. Orography (also known as ''oreography'', ''orology,'' or ''oreology'') falls within the broader discipline of geomorphology. The term orography comes from the Greek: , hill, , to write. Uses Mountain ranges and elevated land masses have a major impact on global climate. For instance, the elevated areas of East Africa substantially determine the strength of the Indian monsoon.Srinivasan, J., Nanjundiah, Ravi S. and Chakraborty, Arindam (2005)"Impact of Orography on the Simulation of Monsoon Climate in a General Circulation Model" Indian Institute of Science. In scientific models, such as general circulation models, orography defines the lower boundary of the model over land. When a river's tributaries or settlements by the river are listed in 'orographic sequence', they are in order from the highest (nearest the source of the river) to t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Honduras
Honduras, officially the Republic of Honduras, is a country in Central America. It is bordered to the west by Guatemala, to the southwest by El Salvador, to the southeast by Nicaragua, to the south by the Pacific Ocean at the Gulf of Fonseca, and to the north by the Gulf of Honduras, a large inlet of the Caribbean Sea. Its Capital city, capital and largest city is Tegucigalpa. Honduras was home to several important Mesoamerican cultures, most notably the Maya civilization, Maya, before Spanish colonization of the Americas, Spanish colonization in the sixteenth century. The Spanish introduced Catholic Church, Catholicism and the now predominant Spanish language, along with numerous customs that have blended with the indigenous culture. Honduras became independent in 1821 and has since been a republic, although it has consistently endured much social strife and political instability, and remains one of the poorest countries in the Western Hemisphere. In 1960, the northern part o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cycas
''Cycas'' is a genus of cycad, and the only genus in the family Cycadaceae with all other genera of cycad being divided between the Stangeriaceae and Zamiaceae families. '' 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. As of April 2024, there are 119 accepted species within the genus ''Cycas'', all of which are native to Asia, Oceania, and eastern Africa and the Indian ocean region, with the largest number of species native to Australia, China and Vietnam.The World List of Cycads (WLoC), a comprehensive taxonomic reference for cycad taxonomy, nomenclature, biology, and literature. The WLoC is produced under the auspices of thIUCN/SSC Cycad Specialist Group (CSG) The online edition is hosted and sponsored bMontgomery Botanical Center Calonje M, Stevenson DW, Osborne R. The World List of Cycads, online edition nternet 2013-2024. ited 2024 Apr 21 Available fromhttp://www.cyca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trichomes
Trichomes (; ) are fine outgrowths or appendages on plants, algae, lichens, and certain protists. They are of diverse structure and function. Examples are hairs, glandular hairs, scales, and papillae. A covering of any kind of hair on a plant is an indumentum, and the surface bearing them is said to be Leaf#Surface, pubescent. Algal trichomes Certain, usually filamentous, algae have the terminal cell (biology), cell produced into an elongate hair-like structure called a trichome. The same term is applied to such structures in some cyanobacteria, such as ''Spirulina (dietary supplement), Spirulina'' and ''Oscillatoria''. The trichomes of cyanobacteria may be unsheathed, as in ''Oscillatoria'', or sheathed, as in ''Calothrix''. These structures play an important role in preventing soil erosion, particularly in cold desert climates. The filamentous sheaths form a persistent sticky network that helps maintain soil structure. Plant trichomes Plant trichomes have many diff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stangeria Eriopus
''Stangeria eriopus'' is a cycad endemic to southern Africa. It is the sole species in the genus ''Stangeria'', most closely related to the Australian genus '' Bowenia'', with which it forms the family Stangeriaceae. Description ''Stangeria eriopus'' is a very long-lived, perennial, evergreen cycad. The stalked, feathered, fern-like leaves are between 25 centimeters and two meters long, with the petiole comprising one third to one half of the overall length (in both varieties). They are pinnately-veined, which distinguishes the species from all other cycads. The petiole comprises half the length of the leaf. The young leaves are bent in bud position, the tip appears rolled up. Young leaves are dotted with short, gray hairs (trichomes), which usually fall off quickly and only stick to the petiole. These trichomes are unbranched and transparent or colored. The species occurs as two variable forms or varieties. The forest form, growing in regions with higher rainfall, is characteri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dioon Spinolosum04
''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. Description Dioons are dioecious, palmlike shrubs with cylindrical stems, usually with many leaves. The species in the genus ''Dioon'' are perennial, evergreen cycads with cylindrical stem axis is partially in the ground. The plant is thickened and made of soft wood, rarely having above ground branches. Leaf bases are persistent or shedding to leave smooth bark. The leaves are pinnate, spirally arranged, interspersed with cataphylls, with leaflets not articulated and lacking a midrib. The lower leaflets are often reduced to spines. The sporophylls are not in vertical rows in cones, and the megasporophyll apices are broadly flattened, upturned, and overlapping. Species in the genus Dioon have 2n = 18 chromosomes. The largest species is '' D. spinolosum'', which are over 16 mete ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dioon Tomasellii
''Dioon tomasellii'' is a species of cycad in the family Zamiaceae. It is endemic to Mexico, where it occurs in the states of Durango, Guerrero, Jalisco, Michoacán, and Nayarit Nayarit, officially the Free and Sovereign State of Nayarit, is one of the 31 states that, along with Mexico City, comprise the Political divisions of Mexico, Federal Entities of Mexico. It is divided in Municipalities of Nayarit, 20 municipalit ....Vovides, A. & Chemnick, J. 2010''Dioon tomasellii''.The IUCN Red List of Threatened Species. Version 2015.2. Downloaded on 06 September 2015. This plant grows in oak and pine-oak forest and woodland habitat. Threats to the species include destruction of the habitat for agriculture and overcollection for horticultural purposes. This species was first described in 1984. It was revised in 1997, with one variety being elevated to species status as '' Dioon sonorense''.Chemnick, J., Gregory, T. J., & Salas Morales, S. (1997)A revision of ''Dioon tomasellii'' (Z ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dioon Spinulosum
''Dioon spinulosum'', giant dioon, or gum palm, is a cycad endemic to limestone cliffs and rocky hillsides in the tropical rainforests of Veracruz and Oaxaca, Mexico. It is one of the tallest cycads in the world, growing to 12m in height. The tree is found at low elevations to 300 m above sea level. ''Dioon spinulosum'' prefers well-drained soil with regular water. It will grow in soils containing few nutrients, in soils rich in limestone, and on slopes. It is hardy to USDA Zones 9B – 11. ''Dioon spinulosum'' has pinnate Pinnation (also called pennation) is the arrangement of feather-like or multi-divided features arising from both sides of a common axis. Pinnation occurs in biological morphology, in crystals, such as some forms of ice or metal crystals, and ... leaves that grow to about 5–7 ft (1.5-2.1 m) in length and radiate out from the trunk. The 120-240 leaflets on each leaf are small and flat, have small thorns and taper to a sharp point. References E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
