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Dioon
''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 meters hig ... [...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 meters high ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platyzamia
''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 meters high an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dioon Edule
''Dioon edule'', the chestnut dioon, is a cycad native to Mexico, also known as ''palma de la virgen''. Cycads are among the oldest seed plants and even pre-date the dinosaurs.The United States Botanical Garden It belongs to the Zamiaceae plant family within the order Cycadales. The genus name "Dioon" means "two-egged", referring to the two ovules (see photo below). Two subspecies are known, the nominate subspecies growing in a moister environment than the other: *''Dioon edule'' subsp. ''angustifolium'' *''Dioon edule'' subsp. ''edule'' Anatomy ''Dioon edule'' is easily distinguished from other ''Dioon'' species because it lacks spines on the borders of leaflets. Spines are present on juvenile leaves but are lost when the plant matures. ''D. edule'' has a crown of pinnate (i.e. feathered) leaves which measure around 135 cm long. Lateral budding is present and mucilage, or sap, is excreted from any cut surfaces on the plant body. The plant has a large central medulla a ... [...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 ( es, Estado Libre y Soberano de Nayarit), is one of the 31 states that, along with Mexico City, comprise the Federal Entities of Mexico. It is divided in 20 municipalities and its ....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'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zamiaceae
The Zamiaceae are a family of cycads that are superficially palm or fern-like. They are divided into two subfamilies with eight genera and about 150 species in the tropical and subtropical regions of Africa, Australia and North and South America. The Zamiaceae, sometimes known as zamiads, are perennial, evergreen, and dioecious. They have subterranean to tall and erect, usually unbranched, cylindrical stems, and stems clad with persistent leaf bases (in Australian genera). Their leaves are simply pinnate, spirally arranged, and interspersed with cataphylls. The leaflets are sometimes dichotomously divided. The leaflets occur with several sub-parallel, dichotomously branching longitudinal veins; they lack a mid rib. Stomata occur either on both surfaces or undersurface only. Their roots have small secondary roots. The coralloid roots develop at the base of the stem at or below the soil surface. Male and female sporophylls are spirally aggregated into determinate cones that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palm Tree
The Arecaceae is a family of perennial flowering plants in the monocot order Arecales. Their growth form can be climbers, shrubs, tree-like and stemless plants, all commonly known as palms. Those having a tree-like form are called palm trees. Currently, 181 genera with around 2,600 species are known, most of which are restricted to tropical and subtropical climates. Most palms are distinguished by their large, compound, evergreen leaves, known as fronds, arranged at the top of an unbranched stem. However, palms exhibit an enormous diversity in physical characteristics and inhabit nearly every type of habitat within their range, from rainforests to deserts. Palms are among the best known and most extensively cultivated plant families. They have been important to humans throughout much of history. Many common products and foods are derived from palms. In contemporary times, palms are also widely used in landscaping. In many historical cultures, because of their i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cycad
Cycads are seed plants that typically have a stout and woody (ligneous) trunk with a crown of large, hard, stiff, evergreen and (usually) pinnate leaves. The species are dioecious, that is, individual plants of a species are either male or female. Cycads vary in size from having trunks only a few centimeters to several meters tall. They typically grow very slowly and live very long. Because of their superficial resemblance, they are sometimes mistaken for palms or ferns, but they are not closely related to either group. Cycads are gymnosperms (naked-seeded), meaning their unfertilized seeds are open to the air to be directly fertilized by pollination, as contrasted with angiosperms, which have enclosed seeds with more complex fertilization arrangements. Cycads have very specialized pollinators, usually a specific species of beetle. Both male and female cycads bear cones ( strobili), somewhat similar to conifer cones. Cycads have been reported to fix nitrogen in asso ... [...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 characterize ... [...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 pubescent. Algal trichomes Certain, usually filamentous, algae have the terminal 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'' 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 different features that vary between both species of plants ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cycas
''Cycas'' is a genus of plants belonging to a very ancient lineage, the Cycadophyta, which are not closely related to palms, ferns, trees or any other modern group of plants. They are evergreen perennials which achieved their maximum diversity in the Jurassic and Cretaceous periods, when they were distributed almost worldwide. At the end of the Cretaceous, when the non-avian dinosaurs became extinct, so did most of the cycas in the Northern Hemisphere. ''Cycas'' is the type genus and the only extant genus recognised in the family Cycadaceae. About 113 species are accepted. ''Cycas circinalis'', a species endemic to India, was the first cycad species to be described in western literature, and was the type of the generic name, ''Cycas''. The best-known ''Cycas'' species is '' Cycas revoluta''. Range The genus is native to the Old World, with the species concentrated around the equatorial regions - eastern and southeastern Asia including the Philippines with 10 species (9 of which a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megasporophyll
A sporophyll is a leaf that bears sporangia. Both microphylls and megaphylls can be sporophylls. In heterosporous plants, sporophylls (whether they are microphylls or megaphylls) bear either megasporangia and thus are called megasporophylls, or microsporangia and are called microsporophylls. The overlap of the prefixes and roots makes these terms a particularly confusing subset of botanical nomenclature. Sporophylls vary greatly in appearance and structure, and may or may not look similar to sterile leaves. Plants that produce sporophylls include: '' Alaria esculenta'', a brown alga which shows sporophylls attached near the base of the alga.Dickson, Carola I. 1963. ''British Seaweeds''. The Kew Series. Lycophytes, where sporophylls may be aggregated into strobili (''Selaginella'' and some ''Lycopodium'' and related genera) or distributed singly among sterile leaves ('' Huperzia''). Sporangia are borne in the axil or on the adaxial surface of the sporophyll. In heterosporous mem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Honduras
Honduras, officially the Republic of Honduras, is a country in Central America. The republic of Honduras 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 and largest city is Tegucigalpa. Honduras was home to several important Mesoamerican cultures, most notably the Maya, before the Spanish Colonization in the sixteenth century. The Spanish introduced 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 of what was the Mosquito Coast was transferred from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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