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Cycad
Cycads are seed plants that typically have a stout and woody (ligneous) trunk (botany), trunk with a crown (botany), 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 slowly and have long lifespans. Because of their superficial resemblance to Arecaceae, palms or ferns, they are sometimes mistaken for them, but they are not closely related to either group. Cycads are gymnosperms (naked-seeded), meaning their fertilization, 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 beetle, and more rarely a thrips or a moth. Both male and female cycads bear cones (strobilus, stro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cycadaceae
''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] |
Gymnosperms
The gymnosperms ( ; ) are a group of woody, perennial Seed plant, seed-producing plants, typically lacking the protective outer covering which surrounds the seeds in flowering plants, that include Pinophyta, conifers, cycads, Ginkgo, and gnetophyta, gnetophytes, forming the clade Gymnospermae. The term ''gymnosperm'' comes from the composite word in ( and ), and literally means 'naked seeds'. The name is based on the unenclosed condition of their seeds (called ovules in their unfertilized state). The non-encased condition of their seeds contrasts with the seeds and ovules of flowering plants (angiosperms), which are enclosed within an Ovary (botany), ovary. Gymnosperm seeds develop either on the surface of scales or Leaf, leaves, which are often modified to form Conifer cone, cones, or on their own as in Taxus, yew, ''Torreya'', and ''Ginkgo''. The life cycle of a gymnosperm involves alternation of generations, with a dominant diploid sporophyte phase, and a reduced haploid gam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seed Plant
A seed plant or spermatophyte (; New Latin ''spermat-'' and Greek ' (phytón), plant), also known as a phanerogam (taxon Phanerogamae) or a phaenogam (taxon Phaenogamae), is any plant that produces seeds. It is a category of embryophyte (i.e. land plant) that includes most of the familiar land plants, including the flowering plants and the gymnosperms, but not ferns, mosses, or algae. The term ''phanerogam'' or ''phanerogamae'' is derived from the Greek (), meaning "visible", in contrast to the term "cryptogam" or " cryptogamae" (, and (), 'to marry'). These terms distinguish those plants with hidden sexual organs (cryptogamae) from those with visible ones (phanerogamae). Description The extant spermatophytes form five divisions, the first four of which are classified as gymnosperms, plants that have unenclosed, "naked seeds": * Cycadophyta, the cycads, a subtropical and tropical group of plants, * Ginkgophyta, which includes a single living species of tree in the genus '' ... [...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 gro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adolphe-Théodore Brongniart
Adolphe-Théodore Brongniart () FRS FRSE FGS (14 January 1801 – 18 February 1876) was a French botanist. He was the son of the geologist Alexandre Brongniart and grandson of the architect, Alexandre-Théodore Brongniart. Brongniart's pioneering work on the relationships between extinct and existing plants has earned him the title of father of paleobotany. His major work on plant fossils was his ' (1828–37). He wrote his dissertation on the Buckthorn family (Rhamnaceae), an extant family of flowering plants, and worked at the Muséum national d'Histoire naturelle in Paris until his death. In 1851, he was elected a foreign member of the Royal Swedish Academy of Sciences. This botanist is denoted by the author abbreviation when citing a botanical name. Brongniart's works Brongniart was an indefatigable investigator and a prolific writer of books and memoirs. As early as 1822, he published a paper on the classification and distribution of fossil plants. This was followed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thrips
Thrips (Order (biology) , order Thysanoptera) are minute (mostly long or less), slender insects with fringed wings and unique asymmetrical mouthparts. Entomologists have species description , described approximately 7,700 species. They fly only weakly and their feathery wings are unsuitable for conventional flight; instead, thrips exploit an unusual mechanism, #Flight , clap and fling, to create lift using an unsteady circulation pattern with transient vortices near the wings. Thrips are a functionally diverse group; many of the known species are fungivorous. A small proportion of the species are serious Pest (organism) , pests of commercially important crops. Some of these serve as Disease vector , vectors for over 20 viruses that cause plant disease, especially the Tospoviruses. Many flower-dwelling species bring benefits as pollinators, with some predatory thrips feeding on small insects or mites. In the right conditions, such as in greenhouses, invasive species can expone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arecaceae
The Arecaceae () is a family (biology), family of perennial plant, perennial, flowering plants in the Monocotyledon, monocot order Arecales. Their growth form can be climbing palm, climbers, shrubs, tree-like and stemless plants, all commonly known as palms. Those having a tree-like form are colloquially called palm trees. Currently, 181 Genus, genera with around 2,600 species are known, most of which are restricted to tropics, tropical and subtropics, subtropical climates. Most palms are distinguished by their large, compound, evergreen leaves, known as fronds, arranged at the top of an unbranched stem, except for the Hyphaene genus, who has branched palms. However, palms exhibit an enormous diversity in physical characteristics and inhabit nearly every type of Habitat (ecology), habitat within their range, from rainforests to deserts. Palms are among the best known and most extensively Horticulture, cultivated plant families. They have been important to humans throughout much ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrogen Fixation
Nitrogen fixation is a chemical process by which molecular dinitrogen () is converted into ammonia (). It occurs both biologically and abiological nitrogen fixation, abiologically in chemical industry, chemical industries. Biological nitrogen fixation or ''diazotrophy'' is catalyzed by enzymes called nitrogenases. These enzyme complexes are encoded by the Nif gene, ''Nif'' genes (or ''Nif'' homologs) and contain iron, often with a second metal (usually molybdenum, but sometimes vanadium). Some nitrogen-fixing bacteria have symbiotic relationships with plants, especially legumes, mosses and aquatic ferns such as ''Azolla''. Looser non-symbiotic relationships between diazotrophs and plants are often referred to as associative, as seen in nitrogen fixation on rice roots. Nitrogen fixation occurs between some termites and fungus, fungi. It occurs naturally in the air by means of NOx, NOx production by lightning. Fixed nitrogen is essential to life on Earth. Organic compounds such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cycas Rumphii
''Cycas rumphii'', commonly known as queen sago or the queen sago palm, is a dioecious gymnosperm, a species of cycad in the genus ''Cycas'' native to Indonesia, New Guinea and Christmas Island. Although palm-like in appearance, it is not a palm. Etymology 'Queen sago' alludes to the name 'king sago' given to the related ''Cycas revoluta'', as well as to its use as a source of edible starch. The specific epithet ''rumphii'' honours the German-born Dutch naturalist Georg Eberhard Rumphius (1628–1702), who served first as a military officer with the Dutch East India Company in Ambon, then with the civil merchant service of the same company. Description The cycad is a small tree, growing to about in height, with a trunk diameter of up to . The bark is grey and distinctively fissured into rectangular, or diamond-shaped, segments. The leaves grow from the crown – bright green, glossy, palm-like fronds, long, with 150–200 leaflets on each frond. The spiny petiole is long. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strobilus
A strobilus (: strobili) is a structure present on many land plant species consisting of sporangia-bearing structures densely aggregated along a stem. Strobili are often called cones, but some botanists restrict the use of the term cone to the woody seed strobili of conifers. Strobili are characterized by a central axis (anatomically a stem) surrounded by spirally arranged or decussate structures that may be modified leaves or modified stems. Leaves that bear sporangia are called '' sporophylls'', while sporangia-bearing stems are called '' sporangiophores''. Lycophytes Some members of both of the two modern classes of Lycopodiophyta (Lycopodiopsida and Isoetopsida) produce strobili. In all cases, the lateral organs of the strobilus are microphylls, bearing sporangia. In other lycophytes, ordinary foliage leaves can act as sporophylls, and there are no organized strobili. Diphasiastrum complanatum strobilus (01).jpeg, Strobili of '' Diphasiastrum'' Lycopodium saururus.JPG, S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evergreen
In botany, an evergreen is a plant which has Leaf, foliage that remains green and functional throughout the year. This contrasts with deciduous plants, which lose their foliage completely during the winter or dry season. Consisting of many different species, the unique feature of evergreen plants lends itself to various environments and purposes. Evergreen species There are many different kinds of evergreen plants, including trees, shrubs, and vines. Evergreens include: * Most species of conifers (e.g., pine, Tsuga, hemlock, spruce, and fir), but not all (e.g., larch). * Live oak, holly, and "ancient" gymnosperms such as cycads * Many woody plants from frost-free climates * Rainforest trees * All eucalypts * Lycopodiopsida, Clubmosses and relatives * Most bamboos The Latin binomial term , meaning "always green", refers to the evergreen nature of the plant, for instance: :''Cupressus sempervirens'' (a cypress) :''Lonicera sempervirens'' (a honeysuckle) :''Sequoia sempervirens'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seed
In botany, a seed is a plant structure containing an embryo and stored nutrients in a protective coat called a ''testa''. More generally, the term "seed" means anything that can be Sowing, sown, which may include seed and husk or tuber. Seeds are the product of the ripened ovule, after the embryo sac is fertilization, fertilized by Pollen, sperm from pollen, forming a zygote. The embryo within a seed develops from the zygote and grows within the mother plant to a certain size before growth is halted. The formation of the seed is the defining part of the process of reproduction in seed plants (spermatophytes). Other plants such as ferns, mosses and marchantiophyta, liverworts, do not have seeds and use water-dependent means to propagate themselves. Seed plants now dominate biological Ecological niche, niches on land, from forests to grasslands both in hot and cold climates. In the flowering plants, the ovary ripens into a fruit which contains the seed and serves to disseminate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
