''Selaginella'' is the sole genus of vascular plants in the family Selaginellaceae, the spikemosses or lesser clubmosses. This family is distinguished from Lycopodiaceae (the clubmosses) by having scale-leaves bearing a ligule and by having spores of two types. They are sometimes included in an informal paraphyletic group called the "

fern allies Fern allies are a diverse group of seedless vascular plants that are not true ferns. Like ferns, a fern ally disperses by shedding spores to initiate an alternation of generations. Classification Originally, three or four groups of plants were ...

". '' S. moellendorffii'' is an important

model organism A model organism (often shortened to model) is a non-human species that is extensively studied to understand particular biological phenomena, with the expectation that discoveries made in the model organism will provide insight into the workin ...

. Its genome has been sequenced by the United States Department of Energy's Joint Genome Institute. The name ''Selaginella'' was erected by Palisot de Beauvois solely for the species '' Selaginella selaginoides'', which turns out (with the closely related '' Selaginella deflexa'') to be a clade that is sister to all other ''Selaginellas'', so any definitive subdivision of the species into separate genera leaves two taxa in ''Selaginella'', with the hundreds of other species in new or resurrected genera. ''Selaginella'' occurs mostly in the tropical regions of the world, with a handful of species to be found in the arctic-alpine zones of both hemispheres.

Description

''Selaginella'' species are creeping or ascendant plants with simple, scale-like leaves ( microphylls) on branching stems from which roots also arise. The stems are aerial, horizontally creeping on the substratum (as in '' Selaginella kraussiana''), sub-erect ('' Selaginella trachyphylla'') or erect (as in '' Selaginella erythropus''). The vascular steles are polystelic protosteles. Stem section shows the presence of more than two protosteles. Each stele is made up of

diarch Diarchy (from Greek , ''di-'', "double", and , ''-arkhía'', "ruled"),Occasionally misspelled ''dyarchy'', as in the ''Encyclopaedia Britannica'' article on the colonial British institution duarchy, or duumvirate (from Latin ', "the office of ...

(having two strands of xylem) and

exarch An exarch (; from Ancient Greek ἔξαρχος ''exarchos'', meaning “leader”) was the holder of any of various historical offices, some of them being political or military and others being ecclesiastical. In the late Roman Empire and ea ...

(growing outward in) xylems. The steles are connected with the cortex by means of many tube-like structures called trabeculae, which are modified endodermal cells with casparian strips on their lateral walls. The stems contain no pith. In ''Selaginella'', each microphyll and sporophyll has a small scale-like outgrowth called a

ligule A ligule (from "strap", variant of ''lingula'', from ''lingua'' "tongue") is a thin outgrowth at the junction of leaf and leafstalk of many grasses (Poaceae) and sedges. A ligule is also a strap-shaped extension of the corolla, such as that of a ...

at the base of the upper surface. The plants are heterosporous with spores of two different size classes, known as megaspores and microspores. Unusual for the lycopods, which nearly always have microphylls with a single unbranched vein, the microphylls of a few ''Selaginella'' species contain a branched vascular trace. Under dry conditions, some species of ''Selaginella'' can survive dehydration. In this state, they may roll up into brown balls and be uprooted, but can rehydrate under moist conditions, become green again and resume growth. This phenomenon is known as

poikilohydry Poikilohydry is the lack of ability (structural or functional mechanism) to maintain and/or regulate water content to achieve homeostasis In biology, homeostasis (British English, British also homoeostasis) Help:IPA/English, (/hɒmɪə(ʊ)ˈste ...

, and poikilohydric plants such as ''Selaginella bryopteris'' are sometimes referred to as

resurrection plants A resurrection plant is any poikilohydric plant that can survive extreme dehydration, even over months or years. Examples include: * ''Anastatica hierochuntica'', also known as the Rose of Jericho, a plant species native to deserts of North Africa ...

Taxonomy

Some scientists still place the Selaginellales in the class Lycopodiopsida (often misconstructed as "Lycopsida"). Some modern authors recognize three generic divisions of ''Selaginella'': ''Selaginella'', ''Bryodesma'' Sojak 1992, and ''Lycopodioides'' Boehm 1760. ''Lycopodioides'' would include the North American species ''S. apoda'' and ''S. eclipes'', while ''Bryodesma'' would include ''S. rupestris'' (as ''Bryodesma rupestre''). ''Stachygynandrum'' is also sometimes used to include the bulk of species. The first major attempt to define and subdivide the group was by Palisot de Beauvois in 1803-1805. He established the genus ''Selaginella'' as a monotypic genus, and placed the bulk of species in ''Stachygynandrum''. ''Gymnogynum'' was another monotypic genus, but that name is superseded by his own earlier name of ''Didiclis''. This turns out, today, to be a group of around 45-50 species also known as the ''Articulatae'', since his genus ''Didiclis/Gymnogynum'' was based on '' Selaginella plumosa''. He also described the genus ''Diplostachyum'' to include a group of species similar to ''Selaginella apoda''.

Spring Spring(s) may refer to: Common uses * Spring (season), a season of the year * Spring (device), a mechanical device that stores energy * Spring (hydrology), a natural source of water * Spring (mathematics), a geometric surface in the shape of a ...

inflated the genus ''Selaginella'' to hold all selaginelloid species four decades later. Phylogenetic studies by Korall & Kenrick determined that the ''Euselaginella'' group, comprising solely the type species, '' Selaginella selaginoides'' and a closely related Hawaiian species, '' Selaginella deflexa'', is a basal and anciently diverging sister to all other ''Selaginella'' species. Beyond this, their study split the remainder of species into two broad groups, one including the ''

Bryodesma ''Selaginella'' is the sole genus of vascular plants in the family Selaginellaceae, the spikemosses or lesser clubmosses. This family is distinguished from Lycopodiaceae (the clubmosses) by having scale-leaves bearing a ligule and by having ...

'' species, the '' Articulatae'', section '' Ericetorum'' Jermy and others, and the other centered on the broad ''Stachygynandrum'' group.

Walton & Aston classification

In the ''Manual of Pteridology'', the following classification was used by Walton & Alston: genus: ''Selaginella'' *subgenus: ''Euselaginella'' **group: ''selaginoides'' **group: ''pygmaea'' **group: ''uliginosa'' (''Ericetorum'') **group: ''rupestris'' (''Tetragonostachys'' or ''Bryodesma'') *subgenus: ''Stachygynandrum'' **series: ''Decumbentes'' **series: ''Ascendentes'' **series: ''Sarmentosae'' **series: ''Caulescentes'' **series: ''Circinatae'' **series: ''Articulatae'' *subgenus: ''Homostachys'' *subgenus: ''Heterostachys'' However, this is now known to be highly paraphyletic in most of its groupings. Two recent classifications, employing modern methods of phylogenetic analysis, are as follows:

Weststrand & Korall, 2016 classification

genus: ''Selaginella'' * subgenus: ''Selaginella'' * clade: "Rhizophoric clade" ** clade A *** subgenus ''Rupestrae'' 'Bryodesma'' Sojak or ''Tetragonostachys'' Jermy, ''S.'' section ''Homeophyllae''*** subgenus ''Lepidophyllae'' 'S.'' section ''Lepidophyllae''*** subgenus ''Gymnogynum'' 'S.'' section ''Articulatae''*** subgenus ''Exaltatae'' ncl. ''S.'' section ''Megalosporum'', ''S.'' section ''Myosurus''*** subgenus ''Ericetorum'' 'S.'' section ''Lyallia''** clade B *** subgenus ''Stachygynandrum'' ncl. ''S.'' (''Boreoselaginella''), ''S.'' (''Pulviniella''), ''S.'' (''Heterostachys'')

Zhang & Zhou, 2015 classification

genus: ''Selaginella'' * subgenus: ''Selaginella'' Type: ''S. selaginoides'' (L.) P.Beauv. ex Mart. & Schrank * subgenus: ''Boreoselaginella'' Type: ''S. sanguinolenta'' (L.) Spring * subgenus: ''Ericetorum'' Type: ''S. uliginosa'' (Labill.) Spring ** section: ''Lyallia'' Type: ''S. uliginosa'' (Labill.) Spring ** section: ''Myosurus'' Type: ''S. myosurus'' Alston ** section: ''Megalosporarum'' Type: ''S. exaltata'' (Kunze) Spring ** section: ''Articulatae'' Type: ''S. kraussiana'' (Kunze) A.Braun ** section: ''Homoeophyllae'' Type: ''S. rupestris'' (L.) Spring (=''Bryodesma'' Sojak or ''Tetragonostachys'' Jermy) ** section: ''Lepidophyllae'' Type: ''S. lepidophylla'' (Hook. & Grev.) Spring * subgenus: ''Pulviniella'' Type: ''S. pulvinata'' (Hook. & Grev.) Maxim * subgenus: ''Heterostachys'' Type: ''S. heterostachys'' Baker ** section: ''Oligomacrosporangiatae'' Type: ''Selaginella uncinata'' (Desv. ex Poir.) Spring ** section: ''Auriculatae'' Type: ''S. douglasii'' (Hook. & Grev.) Spring ** section: ''Homostachys'' Type: : ''S. helvetica'' (L.) Link ** section: ''Tetragonostachyae'' Type: ''S. proniflora'' (L.) Baker ** section: ''Heterostachys'' Type: ''S. brachystachya'' (Hook. & Grev.) Spring * subgenus: ''Stachygynandrum'' Type: ''S. flabellata'' (L.) Spring ** section: ''Plagiophyllae'' Type: ''S. biformis'' A.Braun ex Kuhn ** section: ''Circinatae'' Type: ''S. involvens'' (Sw.) Spring ** section: ''Heterophyllae'' Type: ''S. flexuosa'' Spring ** section: ''Austroamericanae'' Type: ''S. hartwegiana'' Spring ** section: ''Pallescentes'' Type: ''S. pallescens'' (C.Presl) Spring ** section: ''Proceres'' Type: ''S. oaxacana'' Spring ** section: ''Ascendentes'' Type: ''S. alopecuroides'' Baker

Species

Selaginella selaginoides - Niitvälja bog

There are about 750 known species of ''Selaginella''. They show a wide range of characters; the genus is overdue for a revision which might include subdivision into several genera. Better-known spikemosses include: *''

Selaginella apoda ''Selaginella apoda'', commonly known as meadow spikemoss, is a perennial lycophyte native to much of the eastern United States and parts of northeastern Mexico. The life cycle is the shortest of the genus ''Selaginella'', as well as one of the s ...

'' – meadow spikemoss; eastern

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

*''

Selaginella arizonica ''Selaginella'' is the sole genus of vascular plants in the family Selaginellaceae, the spikemosses or lesser clubmosses. This family is distinguished from Lycopodiaceae (the clubmosses) by having scale-leaves bearing a ligule and by having ...

'' Maxon – west Texas to Arizona and Sonora, Mexico *'' Selaginella asprella'' *''

Selaginella bifida ''Selaginella bifida'' is a lycophyte native to Rodrigues Island in the Mascarene Islands The Mascarene Islands (, ) or Mascarenes or Mascarenhas Archipelago is a group of islands in the Indian Ocean east of Madagascar consisting of the islan ...

'' – Rodrigues Island *'' Selaginella biformis'' *''

Selaginella bigelovii ''Selaginella bigelovii'' is a species of spikemoss known by the common names bushy spikemoss and Bigelow's spikemoss. It is native to California and Baja California, where it grows in rocky places in many different habitat types, from the coastl ...

'' *''

Selaginella braunii ''Selaginella'' is the sole genus of vascular plants in the family Selaginellaceae, the spikemosses or lesser clubmosses. This family is distinguished from Lycopodiaceae (the clubmosses) by having scale-leaves bearing a ligule and by having h ...

'' – Braun's spikemoss;

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

*'' Selaginella bryopteris'' – sanjeevani; India *''

Selaginella canaliculata ''Selaginella'' is the sole genus of vascular plants in the family Selaginellaceae, the spikemosses or lesser clubmosses. This family is distinguished from Lycopodiaceae (the clubmosses) by having scale-leaves bearing a ligule and by having ...

'' – clubmoss; southeast Asia, Maluku Islands *''

Selaginella carinata ''Selaginella carinata'' is a species of plant in the Selaginellaceae family. It is endemic to Ecuador. Its natural habitat is subtropical or tropical moist montane forests and it is threatened by habitat loss Habitat destruction (also ter ...

'' *''

Selaginella cinerascens ''Selaginella cinerascens'' is a species of spikemoss known by the common names mesa spikemoss, gray spikemoss, and ashy spikemoss. It is native to Baja California as well as some locations just north of the border in San Diego County, Californi ...

'' *''

Selaginella densa ''Selaginella densa'' is a species of spikemoss known by the common names lesser spikemoss, prairie spikemoss, and Rocky Mountains spikemoss. It is native to western North America, where it can be found from Alaska to Ontario, the Dakotas, Texas ...

'' – lesser spikemoss; western North America *''

Selaginella denticulata ''Selaginella denticulata'', or Mediterranean clubmoss, is a non-flowering plant of the spikemoss genus ''Selaginella'' with a wide distribution around the Northern Hemisphere. Description It is in the genus ''Selaginella'' and this creepe ...

'' *'' Selaginella eclipes'' – hidden spikemoss; eastern North America *'' Selaginella elmeri'' *''

Selaginella eremophila ''Selaginella eremophila'' is a species of spikemoss known by the common name desert spikemoss. It is native to the deserts and adjacent mountains around the intersection of California and Arizona with Baja California. It grows in sandy and rocky ...

'' Maxon *'' Selaginella erythropus'' *''

Selaginella galotteii ''Selaginella'' is the sole genus of vascular plants in the family Selaginellaceae, the spikemosses or lesser clubmosses. This family is distinguished from Lycopodiaceae (the clubmosses) by having scale-leaves bearing a ligule and by having ...

'' *'' Selaginella gigantea'' - From Venezuela. *''

Selaginella hansenii ''Selaginella hansenii'' is a species of spikemoss known by the common name Hansen's spikemoss. It is endemic to California where it can be found throughout the central part of the state, from the lowest reaches of the Cascade Range through the ...

'' *'' Selaginella kraussiana'' – Krauss's spikemoss; Africa, Azores *''

Selaginella lepidophylla ''Selaginella lepidophylla'' (syn. ''Lycopodium lepidophyllum'') is a species of desert plant in the spikemoss family (Selaginellaceae). Known as a "resurrection plant", ''S. lepidophylla'' is renowned for its ability to survive almost complete ...

'' – resurrection plant, dinosaur plant, and flower of stone; Chihuahuan Desert,

*'' Selaginella martensii'' – variegated spikemoss *'' Selaginella moellendorffii'' *''

Selaginella oregana ''Selaginella oregana'' is a species of spikemoss known by the common name Oregon spikemoss. It is native to the Pacific Coast of western North America, where it can be found from British Columbia to northern California. It grows in mossy, shady ...

'' *'' Selaginella plana'' – Asian spikemoss; tropical Asia *'' Selaginella poulteri'' *''

Selaginella pulcherrima ''Selaginella pulcherrima'' is a species of plant in the family Selaginellaceae ''Selaginella'' is the sole genus of vascular plants in the family Selaginellaceae, the spikemosses or lesser clubmosses. This family is distinguished from Lyc ...

'' *''

Selaginella rupestris ''Selaginella rupestris'', the northern selaginella sometimes locally known as ledge spike-moss or rock spike-moss, is a species of spike-moss occurring in dry rocky places in eastern North America, including one locality in Greenland Gree ...

'' – rock spikemoss, festoon pine, and northern Selaginella (eastern North America) *''

Selaginella rupincola ''Selaginella'' is the sole genus of vascular plants in the family Selaginellaceae, the spikemosses or lesser clubmosses. This family is distinguished from Lycopodiaceae (the clubmosses) by having scale-leaves bearing a ligule and by having ...

'' Underw. – west Texas to Arizona and Sonora, Mexico *'' Selaginella selaginoides'' – lesser clubmoss; north temperate Europe, Asia and

) *'' Selaginella sericea'' A.Braun – Ecuador *''

Selaginella serpens ''Selaginella serpens'' is a species of plant in the family Selaginellaceae: found mostly in the Caribbean. References serpens Serpens ( grc, , , the Serpent) is a constellation in the northern celestial hemisphere. One of the 48 con ...

'' *''

Selaginella sibirica ''Selaginella sibirica'', the Siberian spikemoss, is a species of spikemoss ''Selaginella'' is the sole genus of vascular plants in the family Selaginellaceae, the spikemosses or lesser clubmosses. This family is distinguished from Lycopod ...

'' *''

Selaginella stellata ''Selaginella stellata'', also recognized by its common name, starry spikemoss or starry spike-moss, is a species of spikemoss of the family Selaginellaceae. It is a type of lycopod that grows naturally in Mexico and Central American countries li ...

'' – starry spikemoss; Mexico, Central America *''

Selaginella substipitata ''Selaginella substipitata'', the stalked spikemoss, is a species of plant in the Selaginellaceae family, endemic to Caribbean islands, Colombia, and Venezuela Venezuela (; ), officially the Bolivarian Republic of Venezuela ( es, link=no, ...

'' *''

Selaginella tamariscina ''Selaginella tamariscina'' is a species of plant in the Selaginellaceae family, endemic to China, India, Japan, Korea, Philippines, Russia (Siberia), Taiwan, and northern Thailand Thailand ( ), historically known as Siam () and offic ...

'' *''

Selaginella tortipila ''Selaginella tortipila'' is a species of clubmoss in the family Selaginellaceae. It is referred to by the common names twistedhair spikemoss or kinky-hair spike-moss, and is a member of an early diverging group of plants. It is native to the So ...

'' *''

Selaginella uliginosa ''Selaginella uliginosa'' is a small perennial plant found in Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian contin ...

'' –

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

*''

Selaginella umbrosa ''Selaginella umbrosa'' is a species of plant in the Selaginellaceae family. Umbrosa is native to South America, ranging from Yucatán to Colombia and Venezuela. It can be found in Barbados and Tobago, where it is most likely not native. It has ...

'' *'' Selaginella uncinata'' – peacock moss, peacock spikemoss, blue spikemoss *''

Selaginella underwoodii ''Selaginella'' is the sole genus of vascular plants in the family Selaginellaceae, the spikemosses or lesser clubmosses. This family is distinguished from Lycopodiaceae (the clubmosses) by having scale-leaves bearing a ligule and by having ...

'' Hieron. – west Texas to Wyoming and west into Arizona *''

Selaginella wallacei ''Selaginella wallacei'' is a species of spikemoss known by the common name Wallace's spikemoss. It is native to western North America from British Columbia to California to Montana, where it can be found in many types of habitat, including open ...

'' *''

Selaginella watsonii ''Selaginella watsonii'' is a species of spikemoss known by the common name Watson's spikemoss. It is native to the western United States, where it grows in many rocky habitat types, including high mountain peaks in alpine climates. This lycophyt ...

'' *'' Selaginella willdenowii'' – Willdenow's spikemoss, peacock fern; southeast Asia A few species of ''Selaginella'' are

desert A desert is a barren area of landscape where little precipitation occurs and, consequently, living conditions are hostile for plant and animal life. The lack of vegetation exposes the unprotected surface of the ground to denudation. About on ...

plants known as "resurrection plants", because they curl up in a tight, brown or reddish ball during dry times, and uncurl and turn green in the presence of moisture. Other species are tropical forest plants that appear at first glance to be ferns.

Cultivation

A number of ''Selaginella'' species are popular plants for cultivation, mostly tropical species. Some of the species popularly cultivated and actively available commercially include: *''S. kraussiana'': golden clubmoss *''S. martensii'': frosty fern *''S. moellendorffii'': gemmiferous spikemoss *''S. erythropus'': red selaginella or ruby-red spikemoss *''S. uncinata'': peacock moss *''S. lepidophylla'': resurrection plant *''S. braunii'': arborvitae fern

References

External links

* * {{Taxonbar, from=Q379743 Lycophyte genera