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Isoetes Echinospora
''Isoetes echinospora'', also known as spiny quillwort, spiny-spored quillwort or spring quillwort is a species of quillwort in the Isoetaceae family, and is the most abundant species in Canada. It can be found in shallow aquatic environments from Labrador and Newfoundland to Alaska, and south to Pennsylvania, Wisconsin, Colorado, and California. In Germany it is found in only two locations: the Feldsee and Lake Titisee, both in the High Black Forest.Information Board at the Feldsee. Recorded on 26 Aug 2015. It bears 10–30 green to yellow leaves and a two-lobed corm. The velum Velum may refer to: Human anatomy * Superior medullary velum, anterior medullary velum or valve of Vieussens, white matter, in the brain, which stretches between the superior cerebellar peduncles ** Frenulum of superior medullary velum, a sligh ... covers one to three quarters of the sporangium, which are long. Round white megaspores are about in diameter and are covered with spines. Kidney-shaped ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quillwort
''Isoetes'', commonly known as the quillworts, is the only extant genus of plants in the family Isoetaceae, which is in the class of lycopods. There are currently 192 recognized species, with a cosmopolitan distribution but with the individual species often scarce to rare. Some botanists split the genus, separating two South American species into the genus ''Stylites'', although molecular data place these species among other species of ''Isoetes'', so that ''Stylites'' does not warrant taxonomic recognition. Species of ''Isoetes'' virtually identical to modern forms have existed since the Jurassic epoch. The name of the genus may also be spelled ''Isoëtes''. The diaeresis (two dots over the e) indicates that the o and the e are to be pronounced in two distinct syllables. Including this in print is optional; either spelling (''Isoetes'' or ''Isoëtes'') is correct. Description Quillworts are mostly aquatic or semi-aquatic in clear ponds and slow-moving streams, though several ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isoetaceae
Isoetaceae is a family including living quillworts (''Isoetes'') and comparable extinct herbaceous lycopsids (''Tomiostrobus ''Tomiostrobus'' is an extinct quillwort genus from the Early Triassic of Australia, China and Russia, which was especially widespread in the aftermath of Permian Triassic mass extinctions. Description ''Tomiostrobus australis'' is prese ...''). References External links * * {{Authority control Lycophytes Plant families ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Feldsee
The Feldsee (also ''Feldbergsee'') is a lake in southern Baden-Württemberg at the foot of the Feldberg east of Freiburg im Breisgau in Germany. It is part of the Southern Black Forest Nature Park. Geology and earth history The Feldsee is a tarn, around 97,500 m2 in area and up to 32 metres deep. It was formed by glaciers of the last ice age. The largest tarn in the Black Forest, it is hemmed in on three sides by steep mountainsides up to 300 metres high. It is almost circular and has a diameter of between 350 and 370 metres. This area of highland at a height of , which is open to the northeast, enabled it to amass and retain the huge quantities of snow that were the cause of this armchair-shaped terrain with its steep back face, level floor and embankment of moraine at the front. The lake formed after the melting of the ice sheet behind the lines of heaped-up glacial debris. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Titisee
The Titisee is a lake in the southern Black Forest in Baden-Württemberg. It covers an area of and is an average of deep. It owes its formation to the Feldberg glacier, the moraines of which were formed in the Pleistocene epoch and nowadays form the shores of the lake. The lake's outflow, at above sea level, is the River Gutach, which merges with the Haslach stream below Kappel to form the Wutach. The waters of the Titisee thus drain eventually into the Upper Rhine between Tiengen and Waldshut. On the north shore lies the spa town of the same name, today a part of the municipality of Titisee-Neustadt. History A glacial lake is created when the glacier remains stationary for a long time and the weight of the glacier excavates the landscape. Where the glacier is less powerful, the subsoil is less excavated and rises. In addition, it is possible that a moraine (deposit of rock material that is transported with the glacier) prevents the runoff. When the ice melts, water is da ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black Forest
The Black Forest (german: Schwarzwald ) is a large forested mountain range in the state of Baden-Württemberg in southwest Germany, bounded by the Rhine Valley to the west and south and close to the borders with France and Switzerland. It is the source of the Danube and Neckar rivers. Its highest peak is the Feldberg with an elevation of above sea level. Roughly oblong in shape, with a length of and breadth of up to , it has an area of about 6,009 km2 (2,320 sq mi). Historically, the area was known for forestry and the mining of ore deposits, but tourism has now become the primary industry, accounting for around 300,000 jobs. There are several ruined military fortifications dating back to the 17th century. History In ancient times, the Black Forest was known as , after the Celtic deity, Abnoba. In Roman times (Late antiquity), it was given the name ("Marcynian Forest", from the Germanic word ''marka'' = "border"). The Black Forest probably represented the bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corm
A corm, bulbo-tuber, or bulbotuber is a short, vertical, swollen underground plant stem that serves as a storage organ that some plants use to survive winter or other adverse conditions such as summer drought and heat (perennation). The word ''cormous'' usually means plants that grow from corms, parallel to the terms ''tuberous'' and ''bulbous'' to describe plants growing from tubers and bulbs. Structure A corm consists of one or more internodes with at least one growing point, generally with protective leaves modified into skins or tunics. The tunic of a corm forms from dead petiole sheaths—remnants of leaves produced in previous years. They act as a covering, protecting the corm from insects, digging animals, flooding, and water loss. The tunics of some species are thin, dry, and papery, at least in young plants, however, in some families, such as ''Iridaceae'', the tunic of a mature corm can be formidable protection. For example, some of the larger species of '' Wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Velum (botany)
A veil or velum, in mycology, is one of several structures in fungi, especially the thin membrane that covers the cap and stalk of an immature mushroom. Encarta Dictionary Veils fall into two categories: * * Universal veil
In mycology, a universal veil is a temporary membranous tissue that fully envelops immature fruiting bodies of certain gilled mushrooms. The developing Caesar's mushroom (''Amanita caesarea''), for example, which may resemble a small white sphe ...
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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] |
Megaspore
Megaspores, also called macrospores, are a type of spore that is present in heterosporous plants. These plants have two spore types, megaspores and microspores. Generally speaking, the megaspore, or large spore, germinates into a female gametophyte, which produces egg cells. These are fertilized by sperm produced by the male gametophyte developing from the microspore. Heterosporous plants include seed plants (gymnosperms and flowering plants), water ferns (Salviniales), spikemosses (Selaginellaceae) and quillworts (Isoetaceae). Megasporogenesis In gymnosperms and flowering plants, the megaspore is produced inside the nucellus of the ovule. During megasporogenesis, a diploid precursor cell, the megasporocyte or megaspore mother cell, undergoes meiosis to produce initially four haploid cells (the megaspores). Angiosperms exhibit three patterns of megasporogenesis: monosporic, bisporic, and tetrasporic, also known as the ''Polygonum'' type, the ''Alisma'' type, and the ''Drusa'' ty ... [...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 call ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isoetes
''Isoetes'', commonly known as the quillworts, is the only extant genus of plants in the family Isoetaceae, which is in the class of lycopods. There are currently 192 recognized species, with a cosmopolitan distribution but with the individual species often scarce to rare. Some botanists split the genus, separating two South American species into the genus ''Stylites'', although molecular data place these species among other species of ''Isoetes'', so that ''Stylites'' does not warrant taxonomic recognition. Species of ''Isoetes'' virtually identical to modern forms have existed since the Jurassic epoch. The name of the genus may also be spelled ''Isoëtes''. The diaeresis (two dots over the e) indicates that the o and the e are to be pronounced in two distinct syllables. Including this in print is optional; either spelling (''Isoetes'' or ''Isoëtes'') is correct. Description Quillworts are mostly aquatic or semi-aquatic in clear ponds and slow-moving streams, though several ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flora Of North America
The ''Flora of North America North of Mexico'' (usually referred to as ''FNA'') is a multivolume work describing the native plants and naturalized plants of North America, including the United States, Canada, St. Pierre and Miquelon, and Greenland. It includes bryophytes and vascular plants. All taxa are described and included in dichotomous keys, distributions of all species and infraspecific taxa are mapped, and about 20% of species are illustrated with line drawings prepared specifically for FNA. It is expected to fill 30 volumes when completed and will be the first work to treat all of the known flora north of Mexico; in 2015 it was expected tha the series would conclude in 2017. Twenty-nine of the volumes have been published as of 2022. Soon after publication, the contents are made available online. FNA is a collaboration of about 1,000 authors, artists, reviewers, and editors from throughout the world. Reception The series has been praised for "the comprehensive treatme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
