A fern is a member of a group of vascular plants 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.
Osmundaceae 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 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. In these genera the sporangia are borne naked on non-laminar pinnules, while Todea and Leptopteris bear sporangia naked on laminar pinnules. Ferns in this family are larger than most other ferns.
Osmunda is a genus of primarily temperate-zone ferns of family Osmundaceae. Five to ten species have been listed for this genus.
Cunninghamia is a genus of one or two living species of evergreen coniferous trees in the cypress family Cupressaceae. They are native to China, northern Vietnam and Laos, and perhaps also Cambodia. They may reach 50 m (160 ft) in height. In vernacular use, it is most often known as Cunninghamia, but is also sometimes called "China-fir". The genus name Cunninghamia honours Dr. James Cunningham, a British doctor who introduced this species into cultivation in 1702 and botanist Allan Cunningham.
Claytosmunda is a genus of fern. It has only one extant species, Claytosmunda claytoniana, the interrupted fern, native to Eastern Asia, Eastern United States, and Eastern Canada.
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.
Osmunda japonica, also called Asian royal fern, is a fern in the genus Osmunda native to east Asia, including Japan, China, Korea, Taiwan, and the far east of Russia on the island of Sakhalin. It is called gobi in Korean, zenmai in Japanese, and zǐqí or juécài in Chinese.
Frond dimorphism refers to a difference in ferns between the fertile and sterile fronds. Since ferns, unlike flowering plants, bear spores on the leaf blade itself, this may affect the form of the frond itself. In some species of ferns, there is virtually no difference between the fertile and sterile fronds, such as in the genus Dryopteris, other than the mere presence of the sori, or fruit-dots, on the back of the fronds. Some other species, such as Polystichum acrostichoides, or some ferns of the genus Osmunda, feature dimorphism on a portion of the frond only. Others, such as some species of Blechnum and Woodwardia, have fertile fronds that are markedly taller than the sterile. Still others, such as Osmunda cinnamomea, or plants of the family Onocleaceae, have fertile fronds that are completely different from the sterile.
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.
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, and the genera are considered distinct. A probable extinct species, Leptopteris estipularis is known from the Early Cretaceous of India.
Wessiea is an extinct morphogenus of fern not placed in a specific family. Wessiea is known from Late Cretaceous and Middle Miocene age fossils found in Central Washington USA and Southern Alberta Canada. Two species are described in the morphogenus, W. oroszii and the type species W. yakimaensis.
Osmunda wehrii is an extinct species of fern in the modern genus Osmunda of the family Osmundaceae. Osmunda wehrii is known from Langhian age Miocene fossils found in Central Washington.
Plenasium banksiifolium is a fern in the family Osmundaceae. The genus Plenasium is recognized in the Pteridophyte Phylogeny Group classification of 2016 (PPG I); however, some sources place all Plenasium species in a more broadly defined Osmunda, treating this species as Osmunda banksiifolia. It is native along the Pacific coast of Asia, being found in the Kamchatka Peninsula, the Ryukyu Islands, Japan, southeast China, Taiwan, the Philippines, Borneo, Sulawesi and Java. P. banksiifolium, which can reach a height of 1.5 m, is the largest species in the genus and has ornamental value.
Anchistea is a genus of leptosporangiate ferns in the family Blechnaceae. It has only one species, Anchistea virginica the Virginia chain fern, which has long creeping, scaly, underground stems or rhizomes giving rise to tall widely separated, deciduous, single leaves. In contrast, the leaves of Osmundastrum cinnamomeum, which can be mistaken for A. virginica, grow in a group from a crown. Also in contrast to O. cinnamomeum the leaves are monomorphic without distinct fertile fronds. The lower petiole or stipe is dark purple to black, shiny and swollen, the upper rachis is dull green. The leaf blade is green and lanceolate, composed of 12 to 23 paired, alternate pinnatifid pinnae. The pinnae are subdivided into 15 to 20 paired segments that are ovate to oblong. The lower rachis is naked for about half its length. The sori or spore-producing bodies are found on the underside of the pinnae and are long and form a double row which outlines the major veins of the pinnae. In common with all ferns, A. virginica exhibits a gametophyte stage in its life cycle and develops a haploid reproductive prothallus as an independent plant. The spores are produced in red-brown sori which line the spaces (areolae) between the costa and costules. Further photographs can be found at the Connecticut Botanical Society and Ontario Ferns websites.
This article records new taxa of fossil plants that are scheduled to be described during the year 2015, as well as other significant discoveries and events related to paleobotany that are scheduled to occur in the year 2015.
This article records new taxa of plants that were described during the year 2014, as well as other significant discoveries and events related to paleobotany that occurred in the year 2014.
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 by other sources. The genus is known from Early Cretaceous to present.
This list of 2013 in paleobotany records new fossil plant taxa that were described during 2013, as well as other significant discoveries and events related to paleobotany that occurred in the year.
Osmundastrum pulchellum is an extinct species of Osmundastrum, leptosporangiate ferns in the family Osmundaceae from the lower Jurassic (Pliensbachian-Toarcian?) Djupadal Formation of Southern Sweden. It remained unstudied for 40 years. It is one of the most exceptional fossil ferns ever found, preserving intact calcified tissue with DNA and cells. Its exceptional preservation has allowed the study of the DNA relationships with extant Osmundaceae ferns, proving a 180-million-year genomic stasis. It has also preserved its biotic interactions and even ongoing mitosis.
This paleobotany list records new fossil plant taxa that were to be described during the year 2012, as well as notes other significant paleobotany discoveries and events which occurred during 2012.
