|
Tristyly
Tristyly is a rare floral polymorphism that consists of three floral morphs that differ in regard to the length of the stamens and style within the flower. This type of floral mechanism is thought to encourage outcross pollen transfer and is usually associated with heteromorphic self-incompatibility to reduce inbreeding. It is an example of heterostyly and reciprocal herkogamy, like distyly, which is the more common form of heterostyly. Darwin first described tristylous species in 1877 in terms of the incompatibility of these three morphs. Description The three floral morphs of tristylous plants are based on the positioning of the male and female reproductive structures, as either long-, mid-, or short-styled morphs. Often this is shortened to L, M and S morphs. There are two different lengths of stamens in each flower morph that oppose the length of the style. For example, in the short-styled morph, the two sets of stamen are arranged in the mid and long position in order to pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tristyly In Eichhornia Paniculata
Tristyly is a rare floral polymorphism that consists of three floral morphs that differ in regard to the length of the stamens and style within the flower. This type of floral mechanism is thought to encourage outcross pollen transfer and is usually associated with heteromorphic self-incompatibility to reduce inbreeding. It is an example of heterostyly and reciprocal herkogamy, like distyly, which is the more common form of heterostyly. Darwin first described tristylous species in 1877 in terms of the incompatibility of these three morphs. Description The three floral morphs of tristylous plants are based on the positioning of the male and female reproductive structures, as either long-, mid-, or short-styled morphs. Often this is shortened to L, M and S morphs. There are two different lengths of stamens in each flower morph that oppose the length of the style. For example, in the short-styled morph, the two sets of stamen are arranged in the mid and long position in order to pre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterostyly
Heterostyly is a unique form of polymorphism and herkogamy in flowers. In a heterostylous species, two or three morphological types of flowers, termed "morphs", exist in the population. On each individual plant, all flowers share the same morph. The flower morphs differ in the lengths of the pistil and stamens, and these traits are not continuous. The morph phenotype is genetically linked to genes responsible for a unique system of self-incompatibility, termed heteromorphic self-incompatibility, that is, the pollen from a flower on one morph cannot fertilize another flower of the same morph. Heterostylous plants having two flower morphs are termed " distylous". In one morph (termed "pin", "longistylous", or "long-styled" flower) the stamens are short and the pistils are long; in the second morph (termed "thrum", "brevistylous", or "short-styled" flower) the stamens are long and the pistils are short; the length of the pistil in one morph equals the length of the stamens in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pontederiaceae
Pontederiaceae is a family of flowering plants. The APG IV system of 2016 (unchanged from the APG III system of 2009, the APG II system of 2003 and the APG system of 1998) places the family in the order Commelinales, in the commelinid clade, in the monocots. It is a small family of heterostylous aquatic plants, occurring in tropical and subtropical waters. Charles Darwin was interested in the specialized form of heterostyly found in the family, known as tristyly. Not all of the species are heterostylous. The family contains two genera with around 40 known species. It is best known for the water hyacinth ('' Pontederia crassipes''), which is an invasive species in many waterways. The highly modified '' Heteranthera gardneri'' is a submerged aquatic with a two-flowered pseudanthium. Taxonomy The two genera within this family are: *'' Heteranthera'' Ruiz & Pav. (including '' Eurystemon'', '' Hydrothrix'', '' Scholleropsis'', and '' Zosterella'') *''Pontederia'' L. (including '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Connaraceae
Connaraceae is a pan-tropical plant family of 19 genera and more than 180 species of largely evergreen trees, woody shrubs and climbers. The family was first described by Robert Brown in 1816 and the name has been conserved. Distribution Connaraceae is a tropical family, the most important genera of which, ''Connarus'' (approximately 80 species) and ''Rourea'' (40-70 species) have a pan-tropical distribution. Their habitat is generally lowland tropical rain forest and savanna. Description Connaraceae are typically evergreen trees, shrubs or climbers. ''Connarus'' is represented by species in all three lifeforms, while ''Rourea'' species are climbers. Their leaves are pinnate, trifoliate or rarely entire, alternate, without stipules and with a pulvinus at the base of the petiole. ''Connarus guianensis'' is economically important for its decorative wood, zebra wood. Genera Fossil record Fossil leaflet impression described as ''Rourea miocaudata'' from India shows close rese ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Self-pollination
Self-pollination is a form of pollination in which pollen from the same plant arrives at the Stigma (botany), stigma of a flower (in flowering plants) or at the ovule (in gymnosperms). There are two types of self-pollination: in autogamy, pollen is transferred to the Stigma (botany), stigma of the same flower; in geitonogamy, pollen is transferred from the anther of one flower to the stigma of another flower on the same flowering plant, or from Microsporangia, microsporangium to ovule within a single (Monoecy, monoecious) gymnosperm. Some plants have mechanisms that ensure autogamy, such as flowers that do not open (cleistogamy), or stamens that move to come into contact with the stigma. The term selfing that is often used as a synonym, is not limited to self-pollination, but also applies to other types of self-fertilization. Occurrence Few plants self-pollinate without the aid of pollen vectors (such as wind or insects). The mechanism is seen most often in some legumes such as p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptic Self-incompatibility
Cryptic self-incompatibility (CSI) is the botanical expression that's used to describe a weakened self-incompatibility (SI) system. CSI is one expression of a mixed mating system in flowering plants. Both SI and CSI are traits that increase the frequency of fertilization of ovules by outcross pollen, as opposed to self-pollen. Background Although the evident product of more outcrossing is a mutual result among SI systems, CSI should not be mistaken for any other form of true SI, such as common gametophytic SI or sporophytic SI. Robert Bowman outlined the distinction when he posited that cryptic SI allows for full seed set via self-pollination when outcross pollen is limited or absent. CSI has been observed to be a significant benefit to flowering plants as it allows plants to avoid inbreeding depression Inbreeding depression is the reduced biological fitness which has the potential to result from inbreeding (the breeding of related individuals). Biological fitness refer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lythrum Salicaria
''Lythrum salicaria'' or purple loosestrifeFlora of NW Europe''Lythrum salicaria'' is a flowering plant belonging to the family Lythraceae. It should not be confused with other plants sharing the name loosestrife that are members of the family Primulaceae. Other names include spiked loosestrife and purple Lythrum. This herbaceous perennial is native to Europe and Asia, and possibly Australia. Etymology and other names The generic name ''Lythrum'' is derived from the Greek ‘lythron’, meaning blood, in reference to the flower colour in some species.Gledhill D. 1985. ''The Names of Plants''. Cambridge University Press However, Pliny (A.D. 23-79) stated that ''Lythrum'' is named for Lysimachus, an army general and friend of Alexander the Great. ‘’Lysimachus’’ is derived from the Greek ‘’lysis’’, meaning ‘’loosing’’ and ‘’mache’’, meaning strife. Mitich LW. 1999. ''Lythrum salicaria'' L. ''Weed Technology'' 13: 843 – 846. The specific epithet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lythraceae
Lythraceae is a family of flowering plants, including 32 genera, with about 620 species of herbs, shrubs, and trees. The larger genera include ''Cuphea'' (275 spp.), ''Lagerstroemia'' (56), ''Nesaea'' (50), ''Rotala'' (45), and ''Lythrum'' (35). It also includes the pomegranate (''Punica granatum'', formerly in Punicaceae) and the water caltrop (''Trapa natans'', formerly in Trapaceae). Lythraceae has a worldwide distribution, with most species in the tropics, but ranging into temperate climate regions as well. The family is named after the type genus, ''Lythrum'', the loosestrifes (e.g. ''Lythrum salicaria'' purple loosestrife) and also includes henna (''Lawsonia inermis''). It now includes the pomegranate, formerly classed in a separate family Punicaceae. The family also includes the widely cultivated crape myrtle trees. Botanically, the leaves are usually in pairs (opposite), and the flower petals emerge from the rim of the calyx tube. The petals often appear crumpled. Ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linaceae
Linaceae is a family of flowering plants. The family is cosmopolitan, and includes about 250 species in 14 genera, classified into two subfamilies: the Linoideae and Hugonioideae (often recognized as a distinct family, the Hugoniaceae). Leaves of the Linaceae are always simple; arrangement varies from alternate (most species) to opposite (in ''Sclerolinon'' and some ''Linum'') or whorled (in some ''Hesperolinon'' and ''Linum'' species). The hermaphroditic, actinomorphic flowers are pentameric or, very rarely, tetrameric (e.g., ''Radiola linoides'', ''Linum keniense''). In the Linoideae, the largest genus is ''Linum'', the flaxes, with 180–200 species including the cultivated flax, ''Linum usitatissimum''. Members of the Linoideae include herbaceous annuals and perennials, as well as woody subshrubs, shrubs, and small trees (''Tirpitzia'') inhabiting temperate and tropical latitudes of Eurasia, Africa, Australia, and the Americas. The largest genus of the Hugonioideae is ''Hugon ... [...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] |
Amaryllidaceae
The Amaryllidaceae are a family of herbaceous, mainly perennial and bulbous (rarely rhizomatous) flowering plants in the monocot order Asparagales. The family takes its name from the genus ''Amaryllis'' and is commonly known as the amaryllis family. The leaves are usually linear, and the flowers are usually bisexual and symmetrical, arranged in umbels on the stem. The petals and sepals are undifferentiated as tepals, which may be fused at the base into a floral tube. Some also display a corona. Allyl sulfide compounds produce the characteristic odour of the onion subfamily (Allioideae). The family, which was originally created in 1805, now contains about 1600 species, divided into about 70–75 genera, 17 tribes and three subfamilies, the Agapanthoideae (agapanthus), Allioideae (onions and chives) and Amaryllidoideae (amaryllis, daffodils, snowdrops). Over time, it has seen much reorganisation and at various times was combined with the related Liliaceae. Since 2009, a very broa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Style (flower)
The stigma () is the receptive tip of a carpel, or of several fused carpels, in the gynoecium of a flower. Description The stigma, together with the style and ovary (typically called the stigma-style-ovary system) comprises the pistil, which is part of the gynoecium or female reproductive organ of a plant. The stigma itself forms the distal portion of the style, or stylodia, and is composed of , the cells of which are receptive to pollen. These may be restricted to the apex of the style or, especially in wind pollinated species, cover a wide surface. The stigma receives pollen and it is on the stigma that the pollen grain germinates. Often sticky, the stigma is adapted in various ways to catch and trap pollen with various hairs, flaps, or sculpturings. The pollen may be captured from the air (wind-borne pollen, anemophily), from visiting insects or other animals ( biotic pollination), or in rare cases from surrounding water (hydrophily). Stigma can vary from long and sl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_naturalised_in_Pennsylvania.jpg "Click for more on -> Lythrum Salicaria")
