Lygodium is a genus of about 40 species of ferns, native to tropical regions across the world, with a few temperate species in eastern Asia and eastern North America. It is the sole genus in the family Lygodiaceae in the Pteridophyte Phylogeny Group classification of 2016. Alternatively, the genus may be placed as the only genus in the subfamily Lygodioideae of a more broadly defined family Schizaeaceae, the family placement used in Plants of the World Online as of November 2019.
Lycopodium is a genus of clubmosses, also known as ground pines or creeping cedars, in the family Lycopodiaceae. Two very different circumscriptions of the genus are in use. In the Pteridophyte Phylogeny Group classification of 2016, Lycopodium is one of nine genera in the subfamily Lycopodioideae, and has from 9 to 15 species. In other classifications, the genus is equivalent to the whole of the subfamily, since it includes all the other genera. There are then more than 40 accepted species.
Lycopodiella is a genus in the clubmoss family Lycopodiaceae. The genus members are commonly called bog clubmosses, describing their wetland habitat. The genus has a cosmopolitan, with centers of diversity in the tropical New World and New Guinea. In the past, the genus was often incorporated within the related genus Lycopodium, but was segregated in 1964. In the Pteridophyte Phylogeny Group classification of 2016, Lycopodiella is placed in the subfamily Lycopodielloideae, along with three other genera. In this circumscription, the genus has about 15 species. Other sources use a wider circumscription, in which the genus is equivalent to the subfamily of PPG I, in which case about 40 species and hybrids are accepted.
Claytosmunda is a genus of fern. It has only one species, Claytosmunda claytoniana, the interrupted fern, native to Eastern Asia and eastern North America, in the Eastern United States and Eastern Canada.
Woodwardia is a genus of ferns in the family Blechnaceae, in the suborder Aspleniineae of the order Polypodiales. Species are known as chain ferns. The genus is native to warm temperate and subtropical regions of the Northern Hemisphere. They are large ferns, with fronds growing to 50–300 cm long depending on the species.
Blechnum, known as hard fern, is a genus of ferns in the family Blechnaceae, subfamily Blechnoideae, according to the Pteridophyte Phylogeny Group classification of 2016. Two very different circumscriptions of the genus are used by different authors. In the PPG I system, based on Gasper et al. (2016), Blechnum is one of 18 genera in the subfamily Blechnoideae, and has about 30 species. Other sources use a very broadly defined Blechnum s.l., including accepting only two other genera in the subfamily. The genus then has about 250 species. In the PPG I circumscription, the genus is mostly neotropical, with a few southern African species.
Thelypteris is a genus of ferns in the subfamily Thelypteridoideae, family Thelypteridaceae, order Polypodiales. Two radically different circumscriptions of the genus are in use as of January 2020. In the Pteridophyte Phylogeny Group classification of 2016, the genus is a very small one with about two species. In other approaches, the genus is the only one in the subfamily Thelypteridoideae, and so includes between 875 and 1083 species.
Isoetes valida, commonly known as the strong quillwort or true quillwort, is an aquatic lycophyte native to eastern North America. It is found primarily in the Appalachian Mountains from Pennsylvania south to Alabama and Georgia. In addition, one collection of the plant was made in a railway ditch in Wilmington, Delaware in the 1860s, but this was most likely an accidental introduction.
Homalosorus is a genus of fern with only one species, Homalosorus pycnocarpos. It may also be referred to by its older synonyms Athyrium pycnocarpon and Diplazium pycnocarpon. Commonly referred to as the narrow-leaved glade fern, narrow-leaved-spleenwort, or glade fern, it is endemic to eastern North America and typically grows in moist woodlands. Once classified in the family Athyriaceae due to its linear, often doubled sori, in the Pteridophyte Phylogeny Group classification of 2016, it is placed in the small family Diplaziopsidaceae, whose other three species are native to east Asia. Other sources place the genus in the subfamily Diplaziopsidoideae of a very broadly defined family Aspleniaceae, equivalent to the suborder Aspleniineae in PPG I.
Crepidomanes intricatum, synonym Trichomanes intricatum, is known as the weft fern. The genus Crepidomanes is accepted in the Pteridophyte Phylogeny Group classification of 2016, but not by some other sources. As of October 2019, Plants of the World Online sank the genus into a broadly defined Trichomanes, treating this species as Trichomanes intricatum.
Palhinhaea cernua, synonym Lycopodiella cernua, is a plant in the family Lycopodiaceae, commonly known as the staghorn clubmoss. The Hawaiian name for the plant is wāwaeʻiole, or "rat's foot". It has a substantial number of scientific synonyms in several genera. The genus Palhinhaea is accepted in the Pteridophyte Phylogeny Group classification of 2016, but not in other classifications which submerge the genus in Lycopodiella.
The genus Dendrolycopodium is a clubmoss genus in the family Lycopodiaceae. In the Pteridophyte Phylogeny Group classification of 2016, it is placed in the subfamily Lycopodioideae. Some sources do not recognize the genus, sinking it into Lycopodium. It is treated as section Obscura when retained within Lycopodium. The genus includes a discrete group of plants with similar morphologies. All have erect to semi-erect, branched stems.
Doodia maxima, also known as the giant rasp fern, occurs in moist open forests in eastern Australia. It was considered to be a natural hybrid. Some sources place the species in the genus Blechnum, others, including the Pteridophyte Phylogeny Group classification of 2016, place it in Doodia.
Dendrolycopodium hickeyi, synonym Lycopodium hickeyi, known as Hickey's tree club-moss or Pennsylvania clubmoss, is a North American species of clubmoss in the family Lycopodiaceae. It is native to eastern and Central Canada and the eastern and north-central United States. The genus Dendrolycopodium is accepted in the Pteridophyte Phylogeny Group classification of 2016, but not in other classifications, which submerge the genus in Lycopodium.
Lateristachys is a genus of lycophytes in the family Lycopodiaceae. In the Pteridophyte Phylogeny Group classification of 2016, it is placed in the subfamily Lycopodielloideae. Some sources do not recognize the genus, sinking it into Lycopodiella. Lateristachys species are native to the Philippines, Australia and New Zealand.
Palhinhaea is a genus of lycophytes in the family Lycopodiaceae. In the Pteridophyte Phylogeny Group classification of 2016, it is placed in the subfamily Lycopodielloideae. Some sources do not recognize the genus, sinking it into Lycopodiella. Palhinhaea species are widespread in the tropics and subtropics.
Pseudolycopodium is a genus of lycophyte in the family Lycopodiaceae with only one species, Pseudolycopodium densum, known as the bushy clubmoss. In the Pteridophyte Phylogeny Group classification of 2016, the genus is placed in the subfamily Lycopodioideae. Some sources do not recognize the genus, sinking it into Lycopodium. Pseudolycopodium densum is native to Australia, the North Island of New Zealand and New Caledonia. It is a spore-bearing vascular plant and grows up to a metre high. It is found in a wide variety of situations, often in high rainfall areas on sandy soils.
Lycopodielloideae is a subfamily in the family Lycopodiaceae in the Pteridophyte Phylogeny Group classification of 2016. It is equivalent to a broad circumscription of the genus Lycopodiella in other classifications. Like all lycophytes, members of the Lycopodielloideae are vascular plants that reproduce by spores.
Phlegmariurus squarrosus is a species of lycophyte in the family Lycopodiaceae. The genus Phlegmariurus is accepted in the Pteridophyte Phylogeny Group classification of 2016, but not in other classifications, which submerge the genus in Huperzia, with this species as Huperzia squarrosa. The species has a wide distribution from the west Indian Ocean, through tropical and subtropical Asia to eastern Australia and the Pacific.
Hemionitis is a genus of ferns in the subfamily Cheilanthoideae of the family Pteridaceae. Its circumscription varies greatly in different systems of fern classification. In the Pteridophyte Phylogeny Group classification of 2016, it was one of more than 20 genera in the subfamily Cheilanthoideae, and was said to have five species. Other sources treat it as the only genus in the subfamily, and so accept about 450 species. With the restricted circumscription, species are native to tropical America.
