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Osmunda
''Osmunda'' is a genus of primarily temperate-zone ferns of family Osmundaceae. Five to ten species have been listed for this genus. Description Completely dimorphic fronds or pinnae (hemidimorphic), green photosynthetic sterile fronds, and non-photosynthetic spore-bearing fertile pinnae, with large, naked sporangia. Because of the large mass of sporangia that ripen uniformly at the same time to a showy golden color, the ferns look as if they are in flower, and so this genus is sometimes called the "flowering ferns". Taxonomy ''Osmunda'', the type genus of the fern order, Osmundales has historically been the largest genus in the family Osmundaceae. Smith et al. (2006), who carried out the first higher-level pteridophyte classification published in the molecular phylogenetic era, described three genera in that family, namely ''Osmunda'', ''Leptopteris'', and ''Todea''. The genus has also been treated historically as consisting of a number of subgroups, generally subgenera, ''Os ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osmundaceae
Osmundaceae (royal fern family) is a family of ferns containing four to six extant genera and 18–25 known species. It is the only living family of the order Osmundales in the class Polypodiopsida (ferns) or in some classifications the only order in the class Osmundopsida. This is an ancient (known from the Upper Permian) and fairly isolated group that is often known as the "flowering ferns" because of the striking aspect of the ripe sporangia in ''Claytosmunda'', ''Osmunda'', ''Osmundastrum'', and ''Plensium'' (subtribe Osmundinae). In these genera the sporangia are borne naked on non-laminar pinnules, while ''Todea'' and ''Leptopteris'' (subtribe Todinae) bear sporangia naked on laminar pinnules. Ferns in this family are larger than most other ferns. Description The stems of Osmundaceae contain vascular tissue arranged as an ectophloic siphonostele; that is, a ring of phloem occurs on the outside only of a ring of xylem, which surrounds pith (and no other vascular tissue). S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osmundales
Osmundaceae (royal fern family) is a family of ferns containing four to six extant genera and 18–25 known species. It is the only living family of the order Osmundales in the class Polypodiopsida (ferns) or in some classifications the only order in the class Osmundopsida. This is an ancient (known from the Upper Permian) and fairly isolated group that is often known as the "flowering ferns" because of the striking aspect of the ripe sporangia in ''Claytosmunda'', ''Osmunda'', ''Osmundastrum'', and ''Plensium'' (subtribe Osmundinae). In these genera the sporangia are borne naked on non-laminar pinnules, while ''Todea'' and ''Leptopteris'' (subtribe Todinae) bear sporangia naked on laminar pinnules. Ferns in this family are larger than most other ferns. Description The stems of Osmundaceae contain vascular tissue arranged as an ectophloic siphonostele; that is, a ring of phloem occurs on the outside only of a ring of xylem, which surrounds pith (and no other vascular tissue). S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osmundastrum
''Osmundastrum'' is genus of leptosporangiate ferns in the family Osmundaceae with one living species, ''Osmundastrum cinnamomeum'', the cinnamon fern. It is native to the Americas and eastern Asia, growing in swamps, bogs and moist woodlands. In North America it occurs from southern Labrador west to Ontario, and south through the eastern United States to eastern Mexico and the West Indies; in South America it occurs west to Peru and south to Paraguay. In Asia it occurs from southeastern Siberia south through Japan, Korea, China and Taiwan to Myanmar, Thailand and Vietnam. ''Osmundastrum cinnamomeum'' has a fossil record extending into the Late Cretaceous of North America, approximately 70 million years ago, making it one of the oldest living plant species. The fossil records of the genus extend into the Triassic. Characteristics ''Osmundastrum cinnamomeum'' is a deciduous herbaceous plant that produces separate fertile and sterile fronds. The sterile fronds are spreading, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osmunda Cinnamomea
''Osmundastrum'' is genus of leptosporangiate ferns in the family Osmundaceae with one living species, ''Osmundastrum cinnamomeum'', the cinnamon fern. It is native to the Americas and eastern Asia, growing in swamps, bogs and moist woodlands. In North America it occurs from southern Labrador west to Ontario, and south through the eastern United States to eastern Mexico and the West Indies; in South America it occurs west to Peru and south to Paraguay. In Asia it occurs from southeastern Siberia south through Japan, Korea, China and Taiwan to Myanmar, Thailand and Vietnam. ''Osmundastrum cinnamomeum'' has a fossil record extending into the Late Cretaceous of North America, approximately 70 million years ago, making it one of the oldest living plant species. The fossil records of the genus extend into the Triassic. Characteristics ''Osmundastrum cinnamomeum'' is a deciduous herbaceous plant that produces separate fertile and sterile fronds. The sterile fronds are spreading, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osmunda Regalis
''Osmunda regalis'', or royal fern, is a species of deciduous fern, native to Europe, Africa and Asia, growing in woodland bogs and on the banks of streams. The species is sometimes known as flowering fern due to the appearance of its fertile fronds. Names The name ''Osmunda'' possibly derives from ''Osmunder'', a Saxon name for the god Thor. The name "royal fern" derives from its being one of the largest and most imposing European ferns. The name has been qualified as "old world royal fern" in some American literature to distinguish it from the closely related American royal fern, '' O. spectabilis''. However this terminology is not found in British literature. Description ''Osmunda regalis'' produces separate fertile and sterile fronds. The sterile fronds are spreading, tall and broad, bipinnate, with 7-9 pairs of pinnae up to long, each pinna with 7-13 pairs of pinnules 2.5-6.5 cm long and 1–2 cm broad. The fertile fronds are erect and shorter, 20–50 cm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Claytosmunda
''Claytosmunda'' is a genus of fern. It has only one extant species, ''Claytosmunda claytoniana'' (synonym ''Osmunda claytoniana''), the interrupted fern, native to Eastern Asia, Eastern United States, and Eastern Canada. The specific epithet is named after the English-born Virginian botanist John Clayton. "Interrupted" describes the gap in middle of the blade left by the fertile portions after they wither and eventually fall off. The plant is known from fossils to have grown in Europe, showing a previous circumboreal distribution. Fragmentary foliage resembling ''Claytosmunda'' has been found in the fossil record as far back as the Triassic. Description ''Claytosmunda claytoniana'' fronds are bipinnate, tall and broad, the blade formed of alternate segments forming an arching blade tightening to a pointed end. The lower end is also slightly thinner than the rest of the frond because the first segments are shorter. Three to seven short, cinnamon-colored fertile segments are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osmunda Claytoniana
''Claytosmunda'' is a genus of fern. It has only one extant species, ''Claytosmunda claytoniana'' ( synonym ''Osmunda claytoniana''), the interrupted fern, native to Eastern Asia, Eastern United States, and Eastern Canada. The specific epithet is named after the English-born Virginian botanist John Clayton. "Interrupted" describes the gap in middle of the blade left by the fertile portions after they wither and eventually fall off. The plant is known from fossils to have grown in Europe, showing a previous circumboreal distribution. Fragmentary foliage resembling ''Claytosmunda'' has been found in the fossil record as far back as the Triassic. Description ''Claytosmunda claytoniana'' fronds are bipinnate, tall and broad, the blade formed of alternate segments forming an arching blade tightening to a pointed end. The lower end is also slightly thinner than the rest of the frond because the first segments are shorter. Three to seven short, cinnamon-colored fertile segments ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fern
A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes except the lycopods, and differ from mosses and other bryophytes by being vascular, i.e., having specialized tissues that conduct water and nutrients and in having life cycles in which the branched sporophyte is the dominant phase. Ferns have complex leaves called megaphylls, that are more complex than the microphylls of clubmosses. Most ferns are leptosporangiate ferns. They produce coiled fiddleheads that uncoil and expand into fronds. The group includes about 10,560 known extant species. Ferns are defined here in the broad sense, being all of the Polypodiopsida, comprising both the leptosporangiate (Polypodiidae) and eusporangiate ferns, the latter group including horsetails, whisk ferns, marattioid ferns, and ophioglossoid ferns. Ferns first ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plenasium
''Plenasium'' is a genus of ferns in the family Osmundaceae. It is recognized in the Pteridophyte Phylogeny Group classification of 2016 (PPG I), but kept within a more broadly circumscribed genus ''Osmunda ''Osmunda'' is a genus of primarily temperate-zone ferns of family Osmundaceae. Five to ten species have been listed for this genus. Description Completely dimorphic fronds or pinnae (hemidimorphic), green photosynthetic sterile fronds, and no ...'' by other sources. The genus is known from Early Cretaceous to present. Taxonomy , the ''Checklist of Ferns and Lycophytes of the World'' accepted the following four species: Phylogeny of ''Plenasium'' The following fossil species are also accepted. * †''P. arnoldii'' (C.N.Mill. 1967) Bomfleur, Grimm & McLoughlin 2017 * †''P. bransonii'' (Tidwell & Medlyn, 1991) Bomfleur, Grimm & McLoughlin 2017 (?Eocene: New Mexico, USA). * †''P. burgii'' (Tidwell & J.E.Skog, 2002) Bomfleur, Grimm & McLoughlin 2017 (Early Cretac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Todea
The fern genus ''Todea'' is known from only two living species. ''Todea barbara'' L., known as the king fern, is native to South Africa, New Zealand, and Australia while ''Todea papuana'' H. is known only from Papua New Guinea. Species in the genus ''Todea'', as ''Leptopteris'', are distinct from other in Osmundaceae in that sporangia are born on laminar pinnules. So far the fossil record of the genus ''Todea'' consists only of the permineralized rhizome ''Todea tidwellii'' from the Lower Cretaceous of Vancouver Island, Canada and the species ''Todea amissa'', known from the Eocene of Patagonia, Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th .... References Bibliography * Nathan Jud, Gar W.Rothwell and Ruth A. Stockey. 2008. "''Todea'' from the Lower Cretaceous of west ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leptopteris
The fern genus ''Leptopteris'' is a small group of plants found growing in the Pacific Islands, New Guinea and Australia. They are similar to ferns in the related genus ''Todea'', and were originally included in that genus. However, the very thin fronds of ''Leptopteris'' differ from the thick leathery fronds of ''Todea The fern genus ''Todea'' is known from only two living species. ''Todea barbara'' L., known as the king fern, is native to South Africa, New Zealand, and Australia while ''Todea papuana'' H. is known only from Papua New Guinea. Species in the gen ...'', and the genera are considered distinct. A probable extinct species, ''Leptopteris estipularis'' is known from the Early Cretaceous of India. Species Species include: * '' L. alpina'' (Baker) C. Chr. * †'' L. estipularis'' (Sharma, Bohra & Singh) Bomfleur, Grimm & McLoughlin * '' L. fraseri'' (Hooker & Grev.) Presl (Crepe fern, Australia) * '' L. hymenophylloides'' (Richard) Presl (Single crepe fern) * '' L. x i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frond
A frond is a large, divided leaf. In both common usage and botanical nomenclature, the leaves of ferns are referred to as fronds and some botanists restrict the term to this group. Other botanists allow the term frond to also apply to the large leaves of cycads, as well as palms (Arecaceae) and various other flowering plants, such as mimosa or sumac. "Frond" is commonly used to identify a large, compound leaf, but if the term is used botanically to refer to the leaves of ferns and algae it may be applied to smaller and undivided leaves. Fronds have particular terms describing their components. Like all leaves, fronds usually have a stalk connecting them to the main stem. In botany, this leaf stalk is generally called a petiole, but in regard to fronds specifically it is called a stipe, and it supports a flattened blade (which may be called a lamina), and the continuation of the stipe into this portion is called the rachis. The blades may be simple (undivided), pinnatifid ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
