A fern is a member of a group of vascular plants that reproduce via spores and have neither seeds nor flowers. They 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.
Schizaeales is an order of ferns.
The order Salviniales is an order of ferns in the class Polypodiopsida.
Marattiaceae is the only family of extant (living) ferns in the order Marattiales. In the Pteridophyte Phylogeny Group classification of 2016, Marattiales is the only order in the subclass Marattiidae. The family has six genera and about 110 species. Many are different in appearance from other ferns, having large fronds and fleshy rootstocks.
The order Cyatheales, which includes the tree ferns, is a taxonomic division of the fern class, Polypodiopsida. No clear morphological features characterize all of the Cyatheales, but DNA sequence data indicate the order is monophyletic. Some species in the Cyatheales have tree-like growth forms from a vertical rhizome, others have shorter or horizontal expanding rhizomes.
The Marsileaceae are a small family of heterosporous aquatic and semi-aquatic ferns, though at first sight they do not physically resemble other ferns. The group is commonly known as the "pepperwort family" or as the "water-clover family" because the leaves of the genus Marsilea superficially resemble the leaves of a four-leaf clover. In all, the family contains 3 genera and 50 to 80 species with most of those belonging to Marsilea.
Salvinia, a genus in the family Salviniaceae, is a floating fern named in honor of Anton Maria Salvini, a 17th-century Italian scientist. Watermoss is a common name for Salvinia. The genus was published in 1754 by Jean-François Séguier, in his description of the plants found round Verona, Plantae Veronenses Twelve species are recognized, at least three of which are believed to be hybrids, in part because their sporangia are found to be empty.
Salviniaceae, is a family of heterosporous ferns in the order Salviniales. The Salviniaceae contain the two genera Azolla and Salvinia, with about 20 known species in total. Azolla was previously placed in its own family, Azollaceae, but research has shown Azolla and Salvinia to be sister genera with the likely phylogenic relationship shown in the following diagram.
Archaeopteris is an extinct genus of progymnosperm tree with fern-like leaves. A useful index fossil, this tree is found in strata dating from the Upper Devonian to Lower Carboniferous, the oldest fossils being 385 million years old, and had global distribution.
Pilularia or pillworts is a genus of unusual ferns of family Marsileaceae distributed in North Temperate regions, Ethiopian mountains, and the southern hemisphere in Australia, New Zealand, and western South America.
Marsilea is a genus of approximately 65 species of aquatic ferns of the family Marsileaceae. The name honours Italian naturalist Luigi Ferdinando Marsili (1656–1730).
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.
A sporocarp is a specialised type of structure in the aquatic ferns of the order Salviniales whose primary function is the production and release of spores.
The Polypodiidae, commonly called leptosporangiate ferns, formerly Leptosporangiatae, are one of four subclasses of ferns, and the largest of these, being the largest group of living ferns, including some 11,000 species worldwide. The group has also been treated as the class Pteridopsida or Polypodiopsida, although other classifications assign them a different rank. Older names for the group include Filicidae and Filicales, although at least the "water ferns" were then treated separately.
Marsilea drummondii is a species of fern known by the common name nardoo. It is native to Australia, where it is widespread and common, particularly in inland regions. It is a rhizomatous perennial aquatic fern that roots in mud substrates and produces herbage that floats on the surface of quiet water bodies. It occurs in water up to one metre deep. It occurs in abundance after floods. It can form mats on the water's surface and cover the ground in carpets as floodwaters recede. It is variable in appearance and occurs in many types of wetland habitat. In general the frond is made up of two pairs of leaflets and is borne erect when not floating.
Marsilea quadrifolia is a herbaceous plant found naturally in central and southern Europe, Caucasia, western Siberia, Afghanistan, south-west India, China, Japan, and Vietnam, though it is considered a weed in some parts of the United States, where it has been well established in the northeast for over 100 years. Its common names include four leaf clover; European waterclover (USA); sushni (India); aalaik keerai (Tamil).
P. americana may refer to:
Pilularia globulifera, or pillwort, is an unusual species of fern in the family Marsileaceae. It is native to western Europe, where it grows at the edges of lakes, ponds, ditches and marshes, on wet clay or clay-sand soil, sometimes in water up to 30 cm (12 in) deep.
Marsilea minuta, or dwarf waterclover is a species of aquatic fern in the family Marsileaceae. It is not to be confused with Marsilea minutaE.Fourn. 1880, which is a synonym for Marsilea vestita. Other common names include gelid waterklawer, small water clover, airy pepperwort, and pepperwort, though the lattermost also applies to plants in the genus Lepidium. In French it is called marsilea à quatre feuilles and petite marsilée, the latter appearing to be a calque with the Latin botanical name. In Chinese it is 南国田字草, literally "southern field word grass," referencing the similarity of the leaflet shape to the Chinese character for "field." The Koch Rajbongshi people and Garo people call it shusni shak. It is called 'শুশনি শাক' in Bengali. In parts of India it can be called sunisanakka In Indonesian it is semanggi, but this name also applies to Marsilea crenata. In Japanese it is nangokudenjiso and in Thai it is phakwaen. In Malaysian it is tapak itek. In the Philippines it is kaya-kayapuan.
