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Uvariopsis Congensis
''Uvariopsis congensis'' is a species of plant in the Annonaceae family. It is native to Angola, Cameroon, the Central African Republic, the Democratic Republic of the Congo, Gabon, Ivory Coast, Kenya, Sudan, Uganda, Zambia. Walter Robyns and Jean Ghesquière, the botanists who first formally described the species, named it after the Belgian Congo, now called the Democratic Republic of the Congo, where the specimen they examined was collected in the town of Kisantu near the Inkisi River. Description It is a shrub or small tree reaching 5 meters in height. The branches are hairless and dark-colored. Its elliptical to narrowly oblong, sickle-shaped, papery leaves are 7.5-14 by 2-6 centimeters. The leaves have rounded to wedge-shaped bases and tapering tips. The leaves are hairless, or become hairless at maturity, and dark green. The leaves have 10-12 pairs of secondary veins emanating from their midribs. The secondary veins arch and connect near the margins of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frans Hubert Edouard Arthur Walter Robyns
Frans Hubert Edouard Arthur Walter Robyns (1901-1986), known as Walter Robyns, was a Belgian botanist. His son, André Robyns (1935–2003), was also a botanist. Biography He received his doctorate in sciences at the University of Louvain.BHL Taxonomic literature : a selective guide to botanical publications Robyns spent two long stays at the , travelled in central Africa and performed taxonomic work on many groups of tropical African plants, amongst others: , |
Petiole (botany)
In botany, the petiole () is the stalk that attaches the leaf blade to the stem, and is able to twist the leaf to face the sun. This gives a characteristic foliage arrangement to the plant. Outgrowths appearing on each side of the petiole in some species are called stipules. Leaves with a petiole are said to be petiolate, while leaves lacking a petiole are called sessile or apetiolate. Description The petiole is a stalk that attaches a leaf to the plant stem. In petiolate leaves, the leaf stalk may be long, as in the leaves of celery and rhubarb, or short. When completely absent, the blade attaches directly to the stem and is said to be sessile. Subpetiolate leaves have an extremely short petiole, and may appear sessile. The broomrape family Orobanchaceae is an example of a family in which the leaves are always sessile. In some other plant groups, such as the speedwell genus '' Veronica'', petiolate and sessile leaves may occur in different species. In the grasses (Poaceae), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flora Of The Central African Republic
Flora is all the plant life present in a particular region or time, generally the naturally occurring (indigenous) native plants. Sometimes bacteria and fungi are also referred to as flora, as in the terms ''gut flora'' or ''skin flora''. Etymology The word "flora" comes from the Latin name of Flora, the goddess of plants, flowers, and fertility in Roman mythology. The technical term "flora" is then derived from a metonymy of this goddess at the end of the sixteenth century. It was first used in poetry to denote the natural vegetation of an area, but soon also assumed the meaning of a work cataloguing such vegetation. Moreover, "Flora" was used to refer to the flowers of an artificial garden in the seventeenth century. The distinction between vegetation (the general appearance of a community) and flora (the taxonomic composition of a community) was first made by Jules Thurmann (1849). Prior to this, the two terms were used indiscriminately.Thurmann, J. (1849). ''Essai de Phyt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flora Of Cameroon
Flora is all the plant life present in a particular region or time, generally the naturally occurring (indigenous) native plants. Sometimes bacteria and fungi are also referred to as flora, as in the terms ''gut flora'' or '' skin flora''. Etymology The word "flora" comes from the Latin name of Flora, the goddess of plants, flowers, and fertility in Roman mythology. The technical term "flora" is then derived from a metonymy of this goddess at the end of the sixteenth century. It was first used in poetry to denote the natural vegetation of an area, but soon also assumed the meaning of a work cataloguing such vegetation. Moreover, "Flora" was used to refer to the flowers of an artificial garden in the seventeenth century. The distinction between vegetation (the general appearance of a community) and flora (the taxonomic composition of a community) was first made by Jules Thurmann (1849). Prior to this, the two terms were used indiscriminately.Thurmann, J. (1849). ''Essai de Phy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flora Of Angola
The wildlife of Angola is composed of its flora and fauna. An atlas of the amphibians and reptiles of Angola was published in 2018, and reported 117 species of amphibians and 278 of reptiles. A major book on the biodiversity of Angola was published in 2019, and reported more than 2,000 species of organisms (plants, invertebrates and vertebrate animals), and 1,313 fossil species. Fauna Mammals Birds The avifauna of Angola includes a total of 983 species, of which 14 are endemic, 1 has been introduced by humans, and 4 are rare or accidental. 20 species are globally threatened. The western Angola Endemic Bird Area has 14 range-restricted species. Little is known about the conservation status of the region's birds due to the civil war that has raged in Angola for the last 27 years. The greatest diversity of restricted-range species is found in Cuanza Sul province, and given the uncertainty about their current status, many of these species are listed as Threatened. Gabela B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plants Described In 1933
Plants are predominantly Photosynthesis, photosynthetic eukaryotes of the Kingdom (biology), kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclude the fungi and some algae, as well as the prokaryotes (the archaea and bacteria). By one definition, plants form the clade Viridiplantae (Latin name for "green plants") which is sister of the Glaucophyte, Glaucophyta, and consists of the green algae and Embryophyte, Embryophyta (land plants). The latter includes the flowering plants, conifers and other gymnosperms, ferns and Fern ally, their allies, hornworts, liverworts, and mosses. Most plants are multicellular organisms. Green plants obtain most of their energy from sunlight via photosynthesis by primary chloroplasts that are derived from endosymbiosis with cyanobacteria. Their chloroplasts contain chlorophylls a and b, which gives them their green colo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytotoxicity
Cytotoxicity is the quality of being toxic to cells. Examples of toxic agents are an immune cell or some types of venom, e.g. from the puff adder (''Bitis arietans'') or brown recluse spider (''Loxosceles reclusa''). Cell physiology Treating cells with the cytotoxic compound can result in a variety of cell fates. The cells may undergo necrosis, in which they lose membrane integrity and die rapidly as a result of cell lysis. The cells can stop actively growing and dividing (a decrease in cell viability), or the cells can activate a genetic program of controlled cell death (apoptosis). Cells undergoing necrosis typically exhibit rapid swelling, lose membrane integrity, shut down metabolism, and release their contents into the environment. Cells that undergo rapid necrosis in vitro do not have sufficient time or energy to activate apoptotic machinery and will not express apoptotic markers. Apoptosis is characterized by well defined cytological and molecular events including a change i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetogenin
Acetogenins are a class of polyketide natural products found in plants of the family Annonaceae. They are characterized by linear 32- or 34-carbon chains containing oxygenated functional groups including hydroxyls, ketones, epoxides, tetrahydrofurans and tetrahydropyrans. They are often terminated with a lactone or butenolide. Over 400 members of this family of compounds have been isolated from 51 different species of plants. Many acetogenins are characterized by neurotoxicity. Examples include: * Annonacin * Annonins * Bullatacin * Uvaricin Structure Structurally, acetogenins are a series of C-35/C-37 compounds usually characterized by a long aliphatic chain bearing a terminal methyl-substituted α,β-unsaturated γ-lactone ring, as well as one to three tetrahydrofuran (THF) rings. These THF rings are located along the hydrocarbon chain, along with a number of oxygenated moieties (hydroxyls, acetoxyls, ketones, epoxides) and/or double bonds. Research Acetogenins have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gynoecium
Gynoecium (; ) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more) ''pistils'' and is typically surrounded by the pollen-producing reproductive organs, the stamens, collectively called the androecium. The gynoecium is often referred to as the "female" portion of the flower, although rather than directly producing female gametes (i.e. egg cells), the gynoecium produces megaspores, each of which develops into a female gametophyte which then produces egg cells. The term gynoecium is also used by botanists to refer to a cluster of archegonia and any associated modified leaves or stems present on a gametophyte shoot in mosses, liverworts, and hornworts. The corresponding terms for the male parts of those plants are clusters of antheridia within the androecium. Flowers that bear a gynoecium but no stamens are called ''pi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stamen
The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filament and an anther which contains ''sporangium, microsporangia''. Most commonly anthers are two-lobed and are attached to the filament either at the base or in the middle area of the anther. The sterile tissue between the lobes is called the connective, an extension of the filament containing conducting strands. It can be seen as an extension on the dorsal side of the anther. A pollen grain develops from a microspore in the microsporangium and contains the male gametophyte. The stamens in a flower are collectively called the androecium. The androecium can consist of as few as one-half stamen (i.e. a single locule) as in ''Canna (plant), Canna'' species or as many as 3,482 stamens which have been counted in the saguaro (''Carnegiea gigantea'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whorl (botany)
In botany, a whorl or verticil is an arrangement of leaves, sepals, petals, stamens, or carpels that radiate from a single point and surround or wrap around the stem or stalk. A leaf whorl consists of at least three elements; a pair of opposite leaves is not called a whorl. For leaves to grow in whorls is fairly rare except in plant species with very short internodes and some other genera (Galium, Nerium, Elodea etc.). Leaf whorls occur in some trees such as ''Brabejum stellatifolium'' and other species in the family Proteaceae (e.g., in the genus ''Banksia''). In plants such as these, crowded internodes within the leaf whorls alternate with long internodes between the whorls. The morphology of most flowers (called cyclic flowers) is based on four types of whorls: # The calyx: zero or more whorls of sepals at the base # The corolla: zero or more whorls of petals above the calyx # The androecium: zero or more whorls of stamens, each comprising a filament and an anther # The gyn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Axillary Bud
The axillary bud (or lateral bud) is an embryonic or organogenic shoot located in the axil of a leaf. Each bud has the potential to form shoots, and may be specialized in producing either vegetative shoots (stems and branches) or reproductive shoots (flowers). Once formed, a bud may remain dormant for some time, or it may form a shoot immediately. Overview An axillary bud is an embryonic or organogenic shoot which lies dormant at the junction of the stem and petiole of a plant. It arises exogenously from outer layer of cortex of the stem. Axillary buds do not become actively growing shoots on plants with strong apical dominance (the tendency to grow just the terminal bud on the main stem). Apical dominance occurs because the shoot apical meristem produces auxin which prevents axillary buds from growing. The axillary buds begin developing when they are exposed to less auxin, for example if the plant naturally has weak apical dominance, if apical dominance is broken by removi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
