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Anther
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 '' 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'' species or as many as 3,482 stamens which have been counted in the saguaro (''Carnegiea gigantea''). The androecium in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechanism for the union of sperm with eggs. Flowers may facilitate outcrossing (fusion of sperm and eggs from different individuals in a population) resulting from cross-pollination or allow selfing (fusion of sperm and egg from the same flower) when self-pollination occurs. There are two types of pollination: self-pollination and cross-pollination. Self-pollination occurs when the pollen from the anther is deposited on the stigma of the same flower, or another flower on the same plant. Cross-pollination is when pollen is transferred from the anther of one flower to the stigma of another flower on a different individual of the same species. Self-pollination happens in flowers where the stamen and carpel mature at the same time, and are posi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pollen
Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametophytes during the process of their movement from the stamens to the pistil of flowering plants, or from the male cone to the female cone of gymnosperms. If pollen lands on a compatible pistil or female cone, it germinates, producing a pollen tube that transfers the sperm to the ovule containing the female gametophyte. Individual pollen grains are small enough to require magnification to see detail. The study of pollen is called palynology and is highly useful in paleoecology, paleontology, archaeology, and forensics. Pollen in plants is used for transferring haploid male genetic material from the anther of a single flower to the stigma of another in cross-pollination. In a case of self-pollination, this process takes place from the an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microspore
Microspores are land plant spores that develop into male gametophytes, whereas megaspores develop into female gametophytes. The male gametophyte gives rise to sperm cells, which are used for fertilization of an egg cell to form a zygote. Megaspores are structures that are part of the alternation of generations in many seedless vascular cryptogams, all gymnosperms and all angiosperms. Plants with heterosporous life cycles using microspores and megaspores arose independently in several plant groups during the Devonian period. Microspores are haploid, and are produced from diploid microsporocytes by meiosis. Morphology The microspore has three different types of wall layers. The outer layer is called the perispore, the next is the exospore, and the inner layer is the endospore. The perispore is the thickest of the three layers while the exospore and endospore are relatively equal in width. Seedless vascular plants In heterosporous seedless vascular plants, modified leaves ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gametophyte
A gametophyte () is one of the two alternating multicellular phases in the life cycles of plants and algae. It is a haploid multicellular organism that develops from a haploid spore that has one set of chromosomes. The gametophyte is the sexual phase in the life cycle of plants and algae. It develops sex organs that produce gametes, haploid sex cells that participate in fertilization to form a diploid zygote which has a double set of chromosomes. Cell division of the zygote results in a new diploid multicellular organism, the second stage in the life cycle known as the sporophyte. The sporophyte can produce haploid spores by meiosis that on germination produce a new generation of gametophytes. Algae In some multicellular green algae (''Ulva lactuca'' is one example), red algae and brown algae, sporophytes and gametophytes may be externally indistinguishable (isomorphic). In ''Ulva'' the gametes are isogamous, all of one size, shape and general morphology. Land ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canna (plant)
''Canna'' or canna lily is the only genus of flowering plants in the family Cannaceae, consisting of 10 species.The Cannaceae of the World, H. Maas-van der Kamer & P.J.M. Maas, BLUMEA 53: 247-318 Cannas are not true lilies, but have been assigned by the APG II system of 2003 to the order Zingiberales in the monocot clade Commelinids, together with their closest relatives, the gingers, spiral gingers, bananas, arrowroots, heliconias, and birds of paradise. The plants have large foliage, so horticulturists have developed selected forms as large-flowered garden plants. Cannas are also used in agriculture as a source of starch for human and animal consumption. Khoshoo, T.N. & Guha, I. - Origin and Evolution of Cultivated Cannas. Vikas Publishing House Although plants of the tropics, most cultivars have been developed in temperate climates and are easy to grow in most countries of the world, as long as they receive at least 6–8 hours average sunlight during the summer, and ... [...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 cal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sporangium
A sporangium (; from Late Latin, ) is an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular. Virtually all plants, fungi, and many other lineages form sporangia at some point in their life cycle. Sporangia can produce spores by mitosis, but in nearly all land plants and many fungi, sporangia are the site of meiosis and produce genetically distinct haploid spores. Fungi In some phyla of fungi, the sporangium plays a role in asexual reproduction, and may play an indirect role in sexual reproduction. The sporangium forms on the sporangiophore and contains haploid nuclei and cytoplasm. Spores are formed in the sporangiophore by encasing each haploid nucleus and cytoplasm in a tough outer membrane. During asexual reproduction, these spores are dispersed via wind and germinate into haploid hyphae. Although sexual reproduction in fungi varies between phyla, for some fungi the sporangium plays an indirect role in sexual reprod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trithuria
''Trithuria'' is a genus of small aquatic herb, which represent the only members of the family Hydatellaceae found in India, Australia, and New Zealand. Most of the 12 formally characterised species of ''Trithuria'' are found in Australia, with the exception of ''T. inconspicua'' and ''T. konkanensis'', which are found in New Zealand and India, respectively.Dmitry D. Sokoloff, Margarita V. Remizowa, Terry D. Macfarlane, and Paula J. Rudall. 2008. "Classification of the early-divergent angiosperm family Hydatellaceae: one genus instead of two, four new species and sexual dimorphism in dioecious taxa". ''Taxon'' 57(1):179-200.Yadav SR, Janarthanam MK. 1995 Trithuria konkanensis (Hydatellaceae), eine neue Art aus Indien. ''Aqua Planta'' 20. (3): 91-97 (1995). Until genetic testing proved otherwise, these plants were believed to be Monocots related to the grasses (Poaceae). They are unique in being the only plants besides Lacandonia schizmatica and L. braziliana in which the stamens ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lacandonia Schismatica
''Lacandonia schismatica'' is a species of mycoheterotrophic plant in the Triuridaceae (although some taxonomists place the genus in a separate family; the Lacandonaceae.). It is endemic to Lacandon Jungle in the State of Chiapas in southern Mexico. It is known from very few populations and is considered endangered by the researchers who investigate this species. It, and its recently discovered relation Lacandonia braziliana, are the only known flowering plants which in its natural population has a spatial inversion of the reproductive floral whorls (ie stamens and carpels): the 2 to 4 stamens are positioned centrally within the flower, and the 60 to 80 carpels arranged in a ring around them. Perhaps even more remarkable than the reversed positions of male and female parts is the unique mode of pollination. The pollin grain never leaves the anther, but sends the pollin tube backwards through the length of the stamen, across the receptacle and then into the pistil from below. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lacandonia Braziliana
''Lacandonia'' is a mycoheterotrophic plant that contains no chlorophyll and has the unusual characteristic of inverted positions of the male (androecium) and female (gynoecium) floral parts, something that had not been seen in any other plants, with the exceptions of '' Trithuria'' and on occasion the related '' Triuris brevistylis''. Description ''Lacandonia '' is a small mycoheterotrophic plant that lacks chlorophyll and has a rhizomatous, mycotrophic habit. This genus exhibits racemous inflorescences and bract-like leaves. The flowers are actinomorphic and are considered "inverted" from the typical flower arrangement–usually 3 (but sometimes two to four) stamens are in the center of the flower surrounded by 60 to 80 pistils. This characteristic where the position of the androecium and the gynoecium are inverted is unique in the known and described taxa of flowering plants.Vázquez-Santana, S., Engleman, E. M., Martínez-Mena, A., and Márquez-Guzmán, J. (1998)Ovule a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Locule
A locule (plural locules) or loculus (plural loculi) (meaning "little place" in Latin) is a small cavity or compartment within an organ or part of an organism (animal, plant, or fungus). In angiosperms (flowering plants), the term ''locule'' usually refers to a chamber within an ovary (gynoecium or carpel) of the flower and fruits. Depending on the number of locules in the ovary, fruits can be classified as ''uni-locular'' (unilocular), ''bi-locular'', ''tri-locular'' or ''multi-locular''. The number of locules present in a gynoecium may be equal to or less than the number of carpels. The locules contain the ovules or seeds. The term may also refer to chambers within anthers containing pollen. In Ascomycete Ascomycota is a phylum of the kingdom Fungi that, together with the Basidiomycota, forms the subkingdom Dikarya. Its members are commonly known as the sac fungi or ascomycetes. It is the largest phylum of Fungi, with over 64,000 species. The defi ... fungi, locules are c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reproductive Organ
A sex organ (or reproductive organ) is any part of an animal or plant that is involved in sexual reproduction. The reproductive organs together constitute the reproductive system. In animals, the testis in the male, and the ovary in the female, are called the ''primary sex organs''. All others are called ''secondary sex organs'', divided between the external sex organs—the genitals or external genitalia, visible at birth in both sexes—and the internal sex organs. Mosses, ferns, and some similar plants have gametangia for reproductive organs, which are part of the gametophyte. The flowers of flowering plants produce pollen and egg cells, but the sex organs themselves are inside the gametophytes within the pollen and the ovule. Coniferous plants likewise produce their sexually reproductive structures within the gametophytes contained within the cones and pollen. The cones and pollen are not themselves sexual organs. Terminology The ''primary sex organs'' are the gonads ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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