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Lacandonia
''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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lacandoniaceae
''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 and s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lacandonia Brasiliana
''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 and s ... [...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] |
Triuridaceae
Triuridaceae are a family of tropical and subtropical flowering plants, including nine genera with a total of approximately 55 known species. All members lack chlorophyll and are mycoheterotrophic (obtain food by digesting intracellular fungi, often erroneously called 'saprophytes'). The heterotrophic lifestyle of these plants has resulted in a loss of xylem vessels and stomata, and a reduction of leaves to scales. The flowers of Triuridaceae have tepals which are fused at the base and contain 10 to many free carpels. Systematics The circumscription of Triuridaceae has been unstable and some taxa may be paraphyletic. Triuridaceae have been allied with Alismataceae (based on the free carpels) but the APG III system (2009) places them among the non-commelinid monocots, in the Order Pandanales. The genus ''Lacandonia'' is sometimes placed in its own family, Lacandoniaceae. Triuridaceae are included in the Kew Royal Botanical Garden World Checklist of Selected Plant Families and ... [...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] |
Androecium
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 var ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 var ... [...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 Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ..., 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' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triuris Brevistylis
''Triuris'' is a genus in the family Triuridaceae. It consists of species that are small and achlorophyllous, occurring in tropical Mexico, Guatemala, and northern South America.Maas van de Kamer, H. & P. J. M. Maas. 2003. Triuridaceae. En: Manual de Plantas de Costa Rica. Vol. 3. B.E. Hammel, M.H. Grayum, C. Herrera & N. Zamora (eds.). Monographs in systematic botany from the Missouri Botanical Garden 93: 839–840. * ''Triuris alata'' Brade - Rio de Janeiro, Yucatán Peninsula * ''Triuris brevistylis'' Donn.Sm. - Yucatán Peninsula, Guatemala * ''Triuris hexophthalma'' Maas - Guyana * ''Triuris hyalina'' Miers - Brazil, Suriname, Colombia, Venezuela References Pandanales genera Parasitic plants Triuridaceae {{Pandanales-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pollen Tube
A pollen tube is a tubular structure produced by the male gametophyte of seed plants when it germinates. Pollen tube elongation is an integral stage in the plant life cycle. The pollen tube acts as a conduit to transport the male gamete cells from the pollen grain—either from the stigma (in flowering plants) to the ovules at the base of the pistil or directly through ovule tissue in some gymnosperms. In maize, this single cell can grow longer than to traverse the length of the pistil. Pollen tubes were first discovered by Giovanni Battista Amici in the 19th century. They are used as a model for understanding plant cell behavior. Research is ongoing to comprehend how the pollen tube responds to extracellular guidance signals to achieve fertilization. Description Pollen tubes are produced by the male gametophytes of seed plants. Pollen tubes act as conduits to transport the male gamete cells from the pollen grain—either from the stigma (in flowering plants) to the ovule ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Receptacle (botany)
In botany, the receptacle refers to vegetative tissues near the end of reproductive stems that are situated below or encase the reproductive organs. Angiosperms In angiosperms, the receptacle or torus (an older term is thalamus, as in Thalamiflorae) is the thickened part of a stem (pedicel) from which the flower organs grow. In some accessory fruits, for example the pome and strawberry, the receptacle gives rise to the edible part of the fruit. The fruit of ''Rubus'' species is a cluster of drupelets on top of a conical receptacle. When a raspberry is picked, the receptacle separates from the fruit, but in blackberries, it remains attached to the fruit. — In the Daisy family (Compositae or Asteraceae), small individual flowers are arranged on a round or dome-like structure that is also called receptacle. Algae and bryophyta In phycology, receptacles occur at the ends of branches of algae mainly in the brown algae or Heterokontophyta in the Order Fucales. They are spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromosome Number
Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respectively, in each homologous chromosome pair, which chromosomes naturally exist as. Somatic cells, tissues, and individual organisms can be described according to the number of sets of chromosomes present (the "ploidy level"): monoploid (1 set), diploid (2 sets), triploid (3 sets), tetraploid (4 sets), pentaploid (5 sets), hexaploid (6 sets), heptaploid or septaploid (7 sets), etc. The generic term polyploid is often used to describe cells with three or more chromosome sets. Virtually all sexually reproducing organisms are made up of somatic cells that are diploid or greater, but ploidy level may vary widely between different organisms, between different tissues within the same organism, and at different stages in an organism's life cycle. Half ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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