|
Osmunda
''Osmunda'' is a genus of primarily temperate-zone ferns of family Osmundaceae. Five to ten species have been listed for this genus. They have existed since the Early Cretaceous. 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 ... [...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). ... [...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). ... [...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, 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 India, 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 ste ... [...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 India, 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 sprea ... [...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. Description Royal fern is a large perennial herb with stout ascending rhizomes that over many years build up a woody, trunk-like base covered by interwoven roots, 1 m or more high. The fronds, or leaves, arise directly from this rhizome and are very large, typically up to 120 cm but exceptionally as much as 400 cm long and 30-40 cm broad. Each frond is bipinnate, with 5–9 pairs of pinnae up to long, each pinna with 7–13 pairs of pinnules long and broad. Many of the fronds have a terminal fertile portion, where the blade is reduced almost to the midrib and densely covered with brown sporangia. The fronds are at first covered with golden-brown hairs which quickly disappear, leaving a smooth, pale green surface to the leaves. V ... [...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] |
Plenasium
''Plenasium'' is a genus of ferns in the family Osmundaceae. It is recognized in the Pteridophyte Phylogeny Group The Pteridophyte Phylogeny Group (PPG) is an informal international group of systematic botanists who collaborate to establish on the classification of pteridophytes ( lycophytes and ferns) that reflects knowledge about plant relationships discove ... classification of 2016 (PPG I), but kept within a more broadly circumscribed genus '' Osmunda'' 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 Cret ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fern
The ferns (Polypodiopsida or Polypodiophyta) are a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. They differ from mosses 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 leaf, leaves called megaphylls that are more complex than the microphylls of clubmosses. Most ferns are leptosporangiate ferns. They produce coiled Fiddlehead fern, 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 (plant), Polypodiidae) and eusporangiate ferns, the latter group including horsetails, Psilotaceae, whisk ferns, marattioid ferns, and ophioglossoid ferns. The fern crown group, consisting of the leptosporangiates and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Todea
The fern genus ''Todea'' is known from only two living species. Species in the genus ''Todea'', as '' Leptopteris'', are distinct from other in Osmundaceae in that sporangia are born on laminar pinnules. Description The species in the genus have a sub-erect stem and coarse, pinnate leaves. Many large sporangia are located on the bottoms of the leaves and are not arranged in sori or covered by an indusium. Species Only two extant species are currently recognised. '' 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. 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, is a country in the southern half of South America. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leptopteris
The ''Leptopteris'' is a small genus of ferns native to the New Guinea, Australia, New Zealand, and the Pacific Islands. 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'', and the genera are considered distinct. A probable extinct species, ''Leptopteris estipularis'' is known from the Early Cretaceous of India. Species There are seven living species and one naturally-occurring interspecific hybrid.''Leptopteris'' C.Presl ''''. Retrieved 21 January 2024. * '' [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pteridophyte
A pteridophyte is a vascular plant (with xylem and phloem) that reproduces by means of spores. Because pteridophytes produce neither flowers nor seeds, they are sometimes referred to as " cryptogams", meaning that their means of reproduction is hidden. They are also the ancestors of the plants we see today. Ferns, horsetails (often treated as ferns), and lycophytes ( clubmosses, spikemosses, and quillworts) are all pteridophytes. However, they do not form a monophyletic group because ferns (and horsetails) are more closely related to seed plants than to lycophytes. "Pteridophyta" is thus no longer a widely accepted taxon, but the term ''pteridophyte'' remains in common parlance, as do ''pteridology'' and ''pteridologist'' as a science and its practitioner, for example by the International Association of Pteridologists and the Pteridophyte Phylogeny Group. Etymology The name ''Pteridophyte'' is a Neo-Latin compound word created by English speakers around 1880. It is for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
