How many species of lycophytes

When broadly circumscribed, the lycophytes represent a line of evolution distinct from that leading to all other vascular plants, the euphyllophytes, such as ferns, gymnosperms and flowering plants. They are defined by two synapomorphies: lateral rather than terminal sporangia often kidney-shaped or reniform , and exarch protosteles, in which the protoxylem is outside the metaxylem rather than vice versa.

The extinct zosterophylls have at most only flap-like extensions of the stem "enations" rather than leaves, whereas extant lycophyte species have microphylls, leaves that have only a single vascular trace vein , rather than the much more complex megaphylls of other vascular plants.

The extinct genus Asteroxylon represents a transition between these two groups: it has a vascular trace leaving the central protostele, but this extends only to the base of the enation. Zosterophylls and extant lycophytes are all relatively small plants, but some extinct species, such as the Lepidodendrales, were tree-like, and formed extensive forests that dominated the landscape and contributed to the formation of coal. Suggested evolution of microphylls: 1 Sawdonia 2 Asteroxylon 3 Leclercqia Within the broadly defined lycophyte group, species placed in the class Lycopodiopsida are distinguished from species placed in the Zosterophyllopsida by the possession of microphylls.

Some zosterophylls, such as the Devonian Zosterophyllum myretonianum, had smooth stems axes. Others, such as Sawdonia ornata, had flap-like extensions on the stems "enations" , but without any vascular tissue.

Asteroxylon, identified as an early lycopodiopsid, had vascular traces that extended to the base of the enations. Species in the genus Leclercqia had fully vascularized microphylls. These are considered to be stages in the evolution of microphylls. Image:Lycopod bark. Image:Lycopsid joggins mcr1. JPG Fossil ''in situ'' [[w:lycopsid lycopsid]], probably [[w:Sigillaria ''Sigillaria'']], with attached [[w:stigmaria stigmarian roots]].

Image:Lycopsid mcr2. File:Zosterophyllum sp. Journal of the Botanical Research Institute of Texas 7: Molecular phylogenetic and morphological affinities of Adiantum senae Pteridaceae. A linear sequence of extant families and genera of lycophytes and ferns. A new species of Thelypteris Thelypteridaceae from southern Bahia, Brazil. Thelypteris amazonica sp.

Nordic Journal of Botany Thelypteris indusiata Thelypteridaceae , a new fern species from Amazonian Brazil. Floristic surveys have also contributed to the increased knowledge of the group, contributing new names to the list of ferns and lycophytes of Brazil. First record of Pellaea ovata Pteridaceae from Brazil. Carvalho et al. New country and regional records from the Brazilian side of Neblina Massif.

Cnemidaria spectabilis Kunze R. Tryon var. It was previously known only for neighbouring countries of Brazil, such as: Venezuela, Guyana, Suriname, and French Guiana.

The methodology used in this study was basically the same as that adopted for the other groups enumerated by Forzza et al.

The responsibility of the coordinators of the group of ferns and lycophytes was to check and complete the data that eventually was not included by experts. Further details regarding the preparation of the new version of the Brazilian List, which was updated until March can be found in BFG The 20 experts who participated in this step contributed to the updates in the following families authors are listed in order of authorship : Anemiaceae J. Mickel, I. Barros, A. Santiago, A. Labiak , Aspleniaceae L.

Sylvestre , Athyriaceae C. Mynssen , Blechnaceae V. Salino , Culcitaceae J. Condack , Cyatheaceae P. Santiago , Cystopteridaceae C. Mynssen , Dennstaedtiaceae P. Schwartsburd , Dicksoniaceae J. Condack , Dryopteridacae J. Prado, L. Sylvestre, A. Salino, J. Condack, P. Windisch, R. Hirai, T. Kieling-Rubio , Equisetaceae A. Almeida , Gleicheniaceae F. Matos , Hemidictyaceae C. Mynssen , Hymenophyllaceae P.

Windisch , Isoetaceae J. Pereira, J. Sylvestre , Lindsaeaceae J. Prado , Lomariopsidaceae I. Pereira , Lycopodiaceae P. Windisch, C.

Pereira , Marattiaceae P. Labiak , Marsileaceae P. Windisch , Metaxyaceae L. Sylvestre , Oleandraceae L. Sylvestre , Ophioglossaceae J. Sylvestre , Osmundaceae L. Sylvestre , Plagiogyriaceae J. Condack , Polypodiaceae P. Labiak, R. Almeida , Psilotaceae L. Sylvestre , Pteridaceae J. Prado , Saccolomataceae P. Schwartsburd , Salviniaceae A. Almeida , Schizaeaceae I. Pereira , Selaginellaceae R. Hirai , Tectariaceae J. Prado , Thelypteridaceae A. Almeida , and Woodsiaceae C.

The diversity of ferns and lycophytes, in this compilation see Brazilian List of Ferns and Lycophytes; supplementary material - DOI: xxxxxx , adds up to a total of 1, species, divided between 1, ferns and lycophytes. Due to recent advances in the classifications of groups e. Figure 1 Comparison between the number of species and the number of endemic species of lycophytes and ferns between the and the versions of the Brazilian List.

The ten most diverse families are: Pteridaceae, with species, followed by Dryopteridaceae , Polypodiaceae , Hymenophyllaceae 90 , Thelypteridaceae 86 , Aspleniaceae 78 , Lycopodiaceae 64 , Selaginellaceae 55 Anemiaceae 51 , and Cyatheaceae 45 Fig. Based on these results, further changes in the data include: Hymenophyllaceae now exceed Thelypteridaceae in number of species; Lycopodiaceae exceeds Anemiaceae and Selaginellaceae, while the number of species of Anemiaceae has been reduced with relation to Fig.

The 36 other families occurring in Brazil are represented by numbers ranging from 32 to one species. Figure 2 The ten most diverse families of ferns and lycophytes total number of species and endemic species in and However, among the ten families with the highest number of endemic taxa, Dryopteridaceae remained the richest, with 89 endemic species, followed by Polypodiaceae 72 , Pteridaceae 71 , Thelypteridaceae 38 , Lycopodiaceae 31 , Anemiaceae 30 , Aspleniaceae 23 , Selaginellaceae 15 , and Cyatheaceae 14 Fig.

There were also changes to the data regarding the Lycopodiaceae, which surpassed Anemiaceae, Selaginellaceae, and Cyatheaceae; and in Hymenophyllaceae where there was a reduction in the number of endemic taxa.

On the other hand, Isoetaceae and Athyriaceae with 18 and 11 species, respectively , which are not among the ten richest families in Brazilian flora, have a high number of endemic species Tab. The other families have numbers ranging from less than 10 endemic species to none. Thumbnail Table 1 Ferns and lycophytes of the twenty richest genera. As mentioned earlier, genera have been recognized in this study, with the 20 genera most diverse encompassing species, of them endemic Tab.

As in the previous study, the three most diverse genera remain Elaphoglossum 87 species , Thelypteris 85 , and Asplenium However, it is noteworthy that the number of species in Elaphoglossum had the highest increase between the first and the second study from 78 species in to 87 in , representing an increment of Allied to this increase, the number of endemic species in this genus also increased from 35 to Other numerical variations that stood out occurred in Anemia , which had 69 species 40 endemic in and was reduced to 51 30 endemic in ; in Cyathea , which jumped from 30 species 19 endemic to 39 13 endemic ; Doryopteris , previously with 27 species 16 endemic , has now 32 20 endemic , and Ctenitis , which was among the most diverse genera in with 17 species, 10 endemic , and was surpassed by Isoetes , now with 23 species 18 endemic.

Due to changes in the classification of Lycopodiaceae, most of the species of the genus Huperzia occurring in Brazil and South America were transferred to Phlegmariurus. Currently, Huperzia is represented in Brazil by a single endemic species, Huperzia catharinae Christ Holub, while in this genus comprised 38 species, 25 endemic to Brazil.

In the current compilation, the species previously mentioned in Huperzia appear in the genus Phlegmariurus 40 species, 23 endemic Tab. The Brazilian biome with the highest number of species continues to be the Atlantic Rainforest, with species, followed by the Amazon Rainforest species , Cerrado , Pantanal 30 , Caatinga 26 , and Pampa eight Fig. It should be noted that in the the Caatinga had exceeded the Pantanal 25 and 18 species, respectively. The Atlantic Rainforest is the area with the largest number of endemic species, followed by the Cerrado, the latter with a concentration of endemism associated to the 'Campo rupestre' vegetation type.

Figure 3 Number of species of ferns and lycophytes by biome recorded in , , and number of endemic species per biome in In the Amazon Rainforest, the greatest diversity is found in the Terra Firme Forest species , with six endemic species. The 'Cerrado latu sensu ' is the vegetation type with the largest number of endemic species in the Cerrado 16 species , followed by the 'Campo rupestre', where eight endemic species are recognized. Regarding the geopolitical regions, there was an evident increase in the number of species and the Southeast region was confirmed as the most diverse, with species in this survey vs.

The other regions also increased their representation: the South showed species vs. Club mosses produce only one type of spore whereas quillworts and spike mosses produce distinct male and female spores. Lycophytes are believed to be the oldest living lineage of vascular plants.

Estimates of their evolution date back to more than million years ago during the Silurian Period, long before gymnosperms and angiosperms. The vast majority of species are now extinct but with more than species still currently living on Earth, the lycophytes have a tremendous ability to adapt to the constantly changing environments on Earth. The club mosses include around species of lycophytes from the class Lycopsida. The vast majority of species are found within a single genus known as Huperzia , which are sometime referred to as the fir mosses.

They are found all around the world, most commonly growing in rainforests on the trunks of trees but some species inhabit Arctic regions and the southern end of South America. The most significant difference between club mosses and other lycophytes is that club mosses only have one type of spore.

The quillworts are a class of around species of plants and almost all species belong to the genus Isoetes. The quillworts rely heavily on water and many species live entirely submerged while others live in seasonally flooded habitats. Quillworts are small herbs with long narrow leaves that are usually between cm long.

Their stems are swollen and grow underground; and their roots grow in clusters from the base of the stem.

Distributed all around the world and having survived for more than million years, many species of quillworts are currently endangered due to habitat loss. The spike mosses are the most diverse group of lycophytes. They include just a single genus, Selaginella , which has a total of around species.

Spike mosses grow on other plants as epiphytes and on the forest floor. They often resemble club mosses although they have two distinct types of spores and a small scale-like growth at the base of their leaves. Learn about animals, plants, evolution, the tree of life, ecology, cells, genetics, fields of biology and more. A confirmation email has been sent to the email address that you just provided. Check your emails and make sure you click the link to get started on our 6-week course.

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Why not test yourself with our quick 20 question quiz. Growth form The three classes of lycophytes all have very different growth forms but they do share a number of characteristics.