Editing Selaginella

{{Short description|Genus of vascular plants in the family Selaginellaceae}}
{{Italic title}}
{{Automatic taxobox
| name = Spikemoss
| oldest_fossil = Late Carboniferous
| image = Selaginella-sp.jpg
| grandparent_authority = [[Karl Anton Eugen Prantl|Prantl]]
| parent_authority = [[Heinrich Moritz Willkomm|Willk.]]
| taxon = Selaginella
| authority = [[Ambroise Marie François Joseph Palisot de Beauvois|P. Beauv.]]
| type_species = ''[[Selaginella selaginoides]]''
| subdivision_ranks = Species
| subdivision = See text.
| synonyms = * ''Bryodesma'' <small>Soják 1992</small>
* ''Carpolepidium'' <small>Palisot de Beauvois 1805</small>
* ''Didiclis'' <small>Palisot de Beauvois 1803</small>
* ''Diplostachyum'' <small>Palisot de Beauvois 1805</small>
* ''Gymnogynum'' <small>Palisot de Beauvois 1804</small>
* ''Heterophyllae'' <small>Spring 1840</small>
* ''Heterophyllium'' <small>Hieronymus ex Börner 1912</small>
* ''Homoeophyllae'' <small>Spring 1840</small>
* ''Homostachys'' <small>Warburg 1900</small>
* ''Hypopterygiopsis'' <small>Sakurai 1943</small>
* ''Lycopodioides'' <small>Boehm. 1760 ex Kuntze 1891</small>
* ''Mirmau'' <small>Adanson 1763</small>
* ''Polycocca'' <small>Hill 1773 nom. superfl.</small>
* ''Selaginoides'' <small>Séguier 1754 nom. rej.</small>
* ''Selago'' <small>Browne 1756 nom. ill.</small>
* ''Stachygynandrum'' <small>Palisot de Beauvois 1804 nom. rej.</small>
* ''Trispermium'' <small>Hill 1773</small>
}}
[[Image:Spikemoss Selaginella Tamariscina curled up.jpg|thumb|Curled up ''Selaginella tamariscina'']]
[[Image:Selaginella-wallacei.JPG|thumbnail|180px|right|Wallace's Selaginella (''Selaginella wallacei'')]]

'''''Selaginella''''', also known as '''spikemosses''' or '''lesser clubmosses''', is a genus of [[lycophyte]]. It is usually treated as the only genus in the family '''Selaginellaceae''', with over 750 known species.

This family is distinguished from [[Lycopodiaceae]] (the clubmosses) by having scale-leaves bearing a ligule and by having [[heterospory|spores of two types]].  They are sometimes included in an informal paraphyletic group called the "[[fern ally|fern allies]]". The species ''[[Selaginella moellendorffii|S. moellendorffii]]'' is an important [[model organism]]. Its genome has been sequenced by the [[United States Department of Energy]]'s [[Joint Genome Institute]].<ref>{{cite web |url=https://genome.jgi.doe.gov/Selmo1/Selmo1.home.html |title=''Selaginella moellendorffii'' v1.0 |year=2007 |work=[[Joint Genome Institute]] |publisher=[[United States Department of Energy]] |access-date=2009-04-08}}</ref> 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.<ref>{{Cite web|url=http://pza.sanbi.org/selaginella-kraussiana|title = Selaginella kraussiana &#124; PlantZAfrica}}</ref> Fossils assignable to the modern genus are known spanning over 300 million years from the Late [[Carboniferous]] to the present.<ref>{{Cite journal |last1=Bek |first1=Jiří |last2=Libertín |first2=Milan |last3=Drábková |first3=Jana |date=June 2009 |title=Selaginella labutae sp. nov., a new compression herbaceous lycopsid and its spores from the Kladno–Rakovník Basin, Bolsovian of the Czech Republic |url=https://linkinghub.elsevier.com/retrieve/pii/S0034666707001649 |journal=Review of Palaeobotany and Palynology |language=en |volume=155 |issue=3–4 |pages=101–115 |doi=10.1016/j.revpalbo.2007.12.010|bibcode=2009RPaPa.155..101B }}</ref>

== 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 [[stele (biology)|steles]] are polystelic [[protostele]]s. Stem section shows the presence of more than two protosteles. Each stele is made up of [[Xylem#Patterns of protoxylem and metaxylem|diarch]] (having two strands of xylem<ref>{{cite web |title=Diarch |url=https://www.thefreedictionary.com/diarch |website=The Free Dictionary}}</ref>) and [[Xylem#Patterns of protoxylem and metaxylem|exarch]] (growing outward in) [[xylem]]s.{{citation needed|date=January 2017}} 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.{{citation needed|date=January 2017}} The stems contain no pith.{{citation needed|date=January 2017}}

In ''Selaginella'', each microphyll and sporophyll has a small scale-like outgrowth called a [[ligule]] at the base of the upper surface.<ref name=Stace>{{cite book|last=Stace|first=C. A.|author-link = Stace, C. A.|year=2010|title=New Flora of the British Isles|edition=Third|publisher=Cambridge University Press|location = Cambridge, U.K.| isbn=9780521707725}}</ref>{{rp|7}} The plants are [[Heterospory|heterosporous]] with spores of two different size classes, known as megaspores and microspores.<ref>{{Cite journal|last1=Petersen|first1=Kurt B.|last2=Burd|first2=Martin|date=2018|title=The adaptive value of heterospory: Evidence from Selaginella|journal=Evolution|language=en|volume=72|issue=5|pages=1080–1091|doi=10.1111/evo.13484|pmid=29645092|s2cid=4800398|issn=1558-5646|doi-access=free}}</ref> In [[Selaginella rupestris]] fertilization takes place while the megaspore is still attached to the parent plant, and is only released after the embryo has produced [[cotyledon]]s and a root.<ref>[https://books.google.no/books?id=98DnyHnucoUC&pg=PA3&dq=S.+apus+S.+rupestris+embryo+sporophyte&hl=no&newbks=1&newbks_redir=0&sa=X&ved=2ahUKEwi87JOVm9SMAxUXIBAIHQfQNCIQ6AF6BAgHEAM#v=onepage&q=S.%20apus%20S.%20rupestris%20embryo%20sporophyte&f=false Tree Breeding for Genetic Improvement of Tropical Tree Species]</ref>

Unusual for the lycopods, which nearly always have [[Microphylls and megaphylls|microphylls]] with a single unbranched vein, the microphylls of a few ''Selaginella'' species contain a branched vascular trace.<ref>{{Cite journal |last1=Wagner |first1=Warren H. |last2=Beitel |first2=Joseph M. |last3=Wagner |first3=Florence S. |date=1982-11-19 |title=Complex Venation Patterns in the Leaves of Selaginella : Megaphyll-Like Leaves in Lycophytes |url=https://www.science.org/doi/10.1126/science.218.4574.793 |journal=Science |language=en |volume=218 |issue=4574 |pages=793–794 |bibcode=1982Sci...218..793W |doi=10.1126/science.218.4574.793 |issn=0036-8075 |pmid=17771037 |s2cid=44904740}}</ref>

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]], and poikilohydric plants such as ''Selaginella bryopteris'' are sometimes referred to as [[resurrection plants]].<ref name="Bailey1916">{{cite book|title=The Standard Cyclopedia of Horticulture|author=Liberty Hyde Bailey|publisher=The Macmillan company |year=1916 |volume=5 |pages=2920–2921; 3639 |url=https://books.google.com/books?id=EpMDAAAAMAAJ&pg=PA2920}}</ref>

There is no evidence of [[Paleopolyploidy|whole genome duplication]] in Selaginella's evolutionary history. Instead they have gone through tandem gene duplications, which is particularly noticeable in genes relevant for desiccation tolerance.<ref name="VanBuren">{{cite journal |last1=VanBuren |first1=Robert |last2=Ching |first2=Man Wai |last3=Ou |first3=Shujun |last4=Pardo |first4=Jeremy |last5=Bryant |first5=Doug |last6=Jiang |first6=Ning |last7=Mockler |first7=Todd C. |last8=Edger |first8=Patrick |last9=Michael |first9=Todd P. |title=Extreme haplotype variation in the desiccation- tolerant clubmoss ''Selaginella lepidophylla'' |journal=Nature Communications |date=2018 |volume=9 |issue=13 |page=13 |doi=10.1038/s41467-017-02546-5|pmid=29296019 |pmc=5750206 |bibcode=2018NatCo...9...13V }}</ref>{{Technical inline|date=May 2024}}

Their chloroplasts are missing about two-thirds of their plastidial [[Transfer RNA|tRNA]] genes, which are instead found in the genome of the [[cell nucleus|nucleus]].<ref>[https://www.pnas.org/doi/10.1073/pnas.2412221121 Extensive import of nucleus-encoded tRNAs into chloroplasts of the photosynthetic lycophyte, Selaginella kraussiana]</ref> The genus is unique among vascular plants in having species with monoplastidic cells, single giant chloroplasts, located mostly in their dorsal epidermal cells, but also in the upper mesophyll of some species. This appears to be a derived traits and an adaptation to low-light conditions, having originated at least twice. Cells with multiplastidic chloroplasts, more than ten chloroplasts per cell, are considered most basal, and are found in species exposed to more light. Oligoplastidic cells, cells with 3 to ten chloroplats, are more adated to weaker light, and the monoplastidic species being the most shade-loving forms. It is estimated that 70% of Selaginella species are monoplastidic. These receive just 0.4~2.1% of full sunlight, while species with multiple chloroplasts live in open places where they on average receive more than 40.5% of full sunlight.<ref>[https://bsapubs.onlinelibrary.wiley.com/doi/10.1002/ajb2.1455 Gigantic chloroplasts, including bizonoplasts, are common in shade-adapted species of the ancient vascular plant family Selaginellaceae]</ref>

== Taxonomy ==
{{More citations needed section|date=April 2021}}
Some scientists still place the Selaginellales in the class [[Lycopodiopsida]] (often misconstructed as "Lycopsida").{{citation needed|date=June 2014}}<ref>{{Cite book |last=Clugston |first=M. |title=Dictionary of Science |publisher=Penguin Reference Library |year=2014 |isbn=978-0-141-98682-1 |edition=4th |location=London |pages=743 |language=en}}</ref><ref>{{Cite book |last=Walker |first=Peter |title=Chambers Science and Technology Dictionary |publisher=Chambers |year=1992 |isbn=0-550-13239-2 |edition=4th |location=Edinburgh NewYork |pages=999 |language=en}}</ref> Some modern authors recognize three generic divisions of ''Selaginella'': ''Selaginella'', ''Bryodesma'' <small>Sojak 1992</small>, and ''Lycopodioides'' <small>Boehm 1760</small>.  ''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.{{citation needed|date=October 2019}}

The first major attempt to define and subdivide the group was by [[Palisot de Beauvois]]<ref>Palisot de Beauvois (1805): ''Prodrome des cinquième et sixième familles de l'Æthéogamie, les mousses, les lycopodes.''</ref> 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''. [[Antoine Frédéric Spring|Spring]] inflated the genus ''Selaginella'' to hold all selaginelloid species four decades later.

Phylogenetic studies by Korall & Kenrick<ref>{{Citation |last1=Korall |first1=P. |last2=Kenrick |first2=P. |year=2002 |title=Phylogenetic relationships in Selaginellaceae based on ''rbcL'' sequences |journal=American Journal of Botany |volume=89 |issue=3 |pages=506–17 |name-list-style=amp |doi=10.3732/ajb.89.3.506|pmid=21665649 |doi-access=free }}</ref><ref>Korall & Kenrick (2004): The phylogenetic history of Selaginellaceae based on DNA sequences from the plastid and nucleus: extreme substitution rates and rate heterogeneity. ''Molecular Phylogenetics and Evolution'', Volume 31, Issue 3, June 2004, Pages 852–864</ref> 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]]'' species, the ''[[Articulatae]]'', section ''[[Ericetorum]]'' <small>Jermy</small> and others, and the other centered on the broad ''Stachygynandrum'' group.

In 2023, Zhou & Zhang suggested that the genus should be broken up into 19 different genera.<ref name=":0" />

{| class="wikitable"
|-
! colspan=1 |  Walton & Aston 1938<ref>Verdoorn, F., ed. (1938): Manual of Pteridology: J. Walton and A. H. G. Alston, Lycopodinae, pp. 500–506. Martinus Nijhoff, The Hague. 640pp, HB.</ref>
! colspan=1 | Weststrand & Korall 2016 <ref>{{Citation |last1=Weststrand |first1=Stina |last2=Korall |first2=Petra |year=2016 |title=A subgeneric classification of ''Selaginella'' (Selaginellaceae) |journal=American Journal of Botany |volume=103 |issue=12 |pages=2160–2169 |doi=10.3732/ajb.1600288|pmid=27999080 |url=http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-300731 |doi-access=free }}</ref>
|-
| style="vertical-align:top|
* 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''
|
* 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'' [incl. ''S.'' section ''Megalosporum'', ''S.'' section ''Myosurus'']
*** subgenus ''Ericetorum'' [''S.'' section ''Lyallia'']
** clade B
*** subgenus ''Stachygynandrum'' [incl. ''S.'' (''Boreoselaginella''), ''S.'' (''Pulviniella''), ''S.'' (''Heterostachys'')]
|}

=== Zhang & Zhou, 2015 classification ===
<ref name=Zhang />
* subgenus: ''Selaginella'' Type: ''S. selaginoides'' <small>(L.) P.Beauv. ex Mart. & Schrank</small>
* subgenus: ''Boreoselaginella'' Type: ''S. sanguinolenta'' <small>(L.) Spring</small>
* subgenus: ''Ericetorum'' Type: ''S. uliginosa'' <small>(Labill.) Spring</small>
** section: ''Lyallia'' Type: ''S. uliginosa'' <small>(Labill.) Spring</small>
** section: ''Myosurus'' Type: ''S. myosurus'' <small>Alston</small>
** section: ''Megalosporarum'' Type: ''S. exaltata'' <small>(Kunze) Spring</small>
** section: ''Articulatae'' Type: ''S. kraussiana'' <small>(Kunze) A.Braun</small>
** section: ''Homoeophyllae'' Type: ''S. rupestris'' <small>(L.) Spring</small> (=''Bryodesma'' <small>Sojak</small> or ''Tetragonostachys'' <small>Jermy</small>)
** section: ''Lepidophyllae'' Type: ''S. lepidophylla'' <small>(Hook. & Grev.) Spring</small>
* subgenus: ''Pulviniella'' Type: ''S. pulvinata'' <small>(Hook. & Grev.) Maxim</small>
* subgenus: ''Heterostachys'' Type: ''S. heterostachys'' <small>Baker</small>
** section: ''Oligomacrosporangiatae''  Type: ''Selaginella uncinata'' <small>(Desv. ex Poir.) Spring</small>
** section: ''Auriculatae'' Type: ''S. douglasii'' <small>(Hook. & Grev.) Spring</small>
** section: ''Homostachys'' Type: : ''S. helvetica'' <small>(L.) Link</small>
** section: ''Tetragonostachyae'' Type: ''S. proniflora'' <small>(L.) Baker</small>
** section: ''Heterostachys''  Type: ''S. brachystachya'' <small>(Hook. & Grev.) Spring</small>
* subgenus: ''Stachygynandrum'' Type: ''S. flabellata'' <small>(L.) Spring</small>
** section: ''Plagiophyllae'' Type: ''S. biformis'' <small>A.Braun ex Kuhn</small>
** section: ''Circinatae'' Type: ''S. involvens'' <small>(Sw.) Spring</small>
** section: ''Heterophyllae'' Type: ''S. flexuosa'' <small>Spring</small>
** section: ''Austroamericanae'' Type: ''S. hartwegiana'' <small>Spring</small>
** section: ''Pallescentes'' Type: ''S. pallescens'' (C.Presl) <small>Spring</small>
** section: ''Proceres'' Type: ''S. oaxacana'' <small>Spring</small>
** section: ''Ascendentes'' Type: ''S. alopecuroides'' <small>Baker</small>

{| class="wikitable"
|-
! colspan=1 | Zhang & Zhou 2015<ref name=Zhang>{{Citation |last1=Zhou |first1=Xin-Mao |last2=Zhang |first2=Li-Bing |year=2015 |title=A classification of ''Selaginella'' (Selaginellaceae) based on molecular (chloroplast and nuclear), macromorphological, and spore features |journal=Taxon |volume=64 |issue=6 |pages=1117–1140 |doi=10.12705/646.2|s2cid=90451945 |doi-access=free }}</ref>
! colspan=1 | Zhou & Zhang 2023<ref name=":0">{{Citation |last1=Zhou |first1=Xin-Mao |last2=Zhang |first2=Li-Bing |year=2023 |title=Phylogeny, character evolution, and classification of Selaginellaceae (lycophytes) |journal=Plant Diversity |volume= 45|issue= 6|pages= 630–684|doi=10.1016/j.pld.2023.07.003 |doi-access=free |pmid=38197007 |pmc=10772194 |bibcode=2023PlDiv..45..630Z }}</ref>
|-
| style="vertical-align:top|
{{Clade | style=font-size:90%;line-height:80%
|label1=''Selaginella''
|1={{clade
  |1=subgenus ''Selaginella''
  |2={{clade
 |1=subgenus ''Boreoselaginella''
    |2={{clade
      |1={{clade
        |label1=subgenus
        |sublabel1=''Gymnogynum''
        |1={{clade
          |1={{clade
            |1={{clade
           |1=section ''Megalosporum''
              |2={{clade
             |1=section ''Myosurus''
             |2=section ''Lyallia''
                 }}
               }}
            |2=section ''Articulatae''
             }}
          |2={{clade
         |1=section ''Lepidophyllae''
         |2=section ''Homeophyllae''
             }}
           }}
         }}
   |2={{clade
     |1=subgenus ''Pulviniella''
  |2={{clade
    |label1=subgenus
    |sublabel1=''Heterostachys''
          |1={{clade
            |1={{clade
              |1=section ''Tetragonostachyae''
              |2=section ''Heterostachys''
               }}
            |2={{clade
              |1={{clade
                |1=section ''Auriculatae''
                |2=section ''Homostachys''
                 }}
              |label2=section
              |sublabel2=''Oligomacrosporangiatae''
              |2={{clade
                |1=''S. braunii'' subclade
                |2={{clade
                  |1=''S. willdenowii'' subclade
                  |2={{clade
                    |1=''S. pennata'' subclade
                    |2={{clade
                      |1=''S. pervillei'' subclade
                      |2={{clade
                        |1=''S. siamensis'' subclade
                        |2=''S. delicatula'' subclade
                         }}
                       }}
                     }}
                   }}
                 }}
               }}
             }}
    |label2=subgenus
    |sublabel2=''Stachygynandrum''
          |2={{clade
            |1=section ''Plagiophyllae''
            |2={{clade
             |1=section ''Circinatae''
              |2={{clade
                |1=section ''Ascendentes''
                |2={{clade
                  |1={{clade
                    |1=section ''Proceres''
                    |2=section ''Pallescentes''
                     }}
                  |2={{clade
                    |1=section ''Austroamericanae''
                    |2=section ''Heterophyllae''
                     }}
                   }}
                 }}
               }}
             }}
     }}
   }}
    }}
  }}
   }}
}}
|
{{Clade | style=font-size:90%;line-height:80%
|label1=Selaginellaceae
|1={{clade
  |1={{clade
    |label1=Selaginoidoideae
    |1=''Selaginoides'' <small>Séguier 1754</small>
     }}
  |2={{clade
    |1={{clade
      |label1=Boreoselaginelloideae
      |1=''Boreoselaginella'' <small>(Warburg 1900) Zhang & Zhou 2023</small>
       }}
    |2={{clade
      |1={{clade
        |label1=Gymnogynoideae
        |1={{clade
          |1={{clade
            |1=''Afroselaginella'' <small>Zhang & Zhou 2023</small>
            |2=''Megaloselaginella'' <small>Zhang & Zhou 2023</small>
             }}
          |2={{clade
            |1={{clade
              |1=''Ericetorum'' <small>(Jermy 1986) Zhang & Zhou 2023</small>
              |2=''Gymnogynum'' <small>Palisot de Beauvois 1804</small>
               }}
            |2={{clade
              |1=''Lepidoselaginella'' <small>Zhang & Zhou 2023</small>
              |2=''Bryodesma'' <small>Soják 1992</small>
               }}
             }}
           }}
         }}
      |2={{clade
        |1={{clade
          |label1=Pulvinielloideae
          |1=''Pulviniella'' <small>(Zhang & Zhou 2015) Zhang & Zhou 2023</small>
          |label2=Sinoselaginelloideae
          |2={{clade
            |1=''Sinoselaginella'' <small>Zhang & Zhou 2023</small>
            |2={{clade
              |1=''Austroselaginella'' <small>Zhang & Zhou 2023</small>
              |2=''Korallia'' <small>Zhang & Zhou 2023</small>
               }}
             }}
           }}
        |2={{clade
          |label1=Lycopodioidoideae
          |1={{clade
            |1={{clade
              |1={{clade
                |1=''Valdespinoa'' <small>Zhang & Zhou 2023</small>
                |2=''Lycopodioides'' <small>Boehm. 1760 ex Kuntze 1891</small>
                 }}
              |2=''Didiclis'' <small>Palisot de Beauvois ex Mirb. 1802</small>
               }}
            |2=''Hypopterygiopsis'' <small>Sakurai 1943</small>
             }}
          |label2=Selaginelloideae
          |2={{clade
            |1=''Chuselaginella'' <small>Zhang & Zhou 2023</small>
            |2={{clade
              |1=''Kungiselaginella'' <small>Zhang & Zhou 2023</small>
              |2={{clade
                |label1=''Selaginella''
                |1={{clade
                  |1={{clade
                    |1={{clade
                      |1=section ''Proceres'' <small>Spring 1850</small>
                      |2=section ''Pallescentes'' <small>Zhang & Zhou 2015</small>
                       }}
                    |2=section ''Austroamericanae'' <small>Zhang & Zhou 2015</small>
                     }}
                  |2=section ''Heterophyllae'' <small>Spring 1840</small>
                   }}
                 }}
               }}
             }}
           }}
         }}
       }}
     }}
   }}
}}
|}

=== Species ===
{{Main|List of Selaginella species}}
[[File:Selaginella canaliculata.jpeg|thumb|''Selaginella canaliculata'']]
[[File:Selaginella selaginoides - Niitvälja bog.jpg|thumb|''Selaginella selaginoides'']]
[[File:Iridescent fern.jpg|thumb|''Selaginella willdenowii'' is known for its iridescent colours]]
There are about 750 known species of ''Selaginella''.<ref name="Christenhusz-Byng2016">{{cite journal |author1=Christenhusz, M. J. M. |author2=Byng, J. W.  |name-list-style=amp | year = 2016 | title = The number of known plants species in the world and its annual increase | journal = Phytotaxa | volume = 261 | pages = 201–217 | url = http://biotaxa.org/Phytotaxa/article/download/phytotaxa.261.3.1/20598 | doi = 10.11646/phytotaxa.261.3.1 | issue = 3 | doi-access = free }}</ref> They show a wide range of characters; the genus is overdue for a revision which might include subdivision into several genera.{{citation needed|date=October 2019}} Species of spikemoss include:
* ''[[Selaginella apoda]]'' – meadow spikemoss; eastern [[North America]]
* ''[[Selaginella arizonica]]'' <small>Maxon</small> – west Texas to Arizona and Sonora, Mexico
* ''[[Selaginella asprella]]''
* ''[[Selaginella bifida]]'' – [[Rodrigues Island]]
* ''[[Selaginella biformis]]''
* ''[[Selaginella bigelovii]]''
* ''[[Selaginella braunii]]'' – Braun's spikemoss; [[China]]
* ''[[Selaginella bryopteris]]'' – sanjeevani; [[India]]
* ''[[Selaginella canaliculata]]'' – clubmoss; [[southeast Asia]], [[Maluku Islands]]
* ''[[Selaginella carinata]]''
* ''[[Selaginella cinerascens]]''
* ''[[Selaginella densa]]'' – lesser spikemoss; western North America
* ''[[Selaginella denticulata]]''
* ''[[Selaginella eclipes]]'' – hidden spikemoss; eastern North America
* ''[[Selaginella elmeri]]''
* ''[[Selaginella eremophila]]'' <small>Maxon</small>
* ''[[Selaginella erythropus]]''
* ''[[Selaginella galotteii]]''
* ''[[Selaginella gigantea]]'' – From Venezuela.
* ''[[Selaginella hansenii]]''
* ''[[Selaginella kraussiana]]'' – Krauss's spikemoss; [[Africa]], [[Azores]]
* ''[[Selaginella lepidophylla]]'' – resurrection plant, dinosaur plant, and flower of stone; [[Chihuahuan Desert]], [[North America]]
* ''[[Selaginella martensii]]'' – variegated spikemoss
* ''[[Selaginella moellendorffii]]''
* ''[[Selaginella oregana]]''
* ''[[Selaginella plana]]'' – Asian spikemoss; tropical [[Asia]]
* ''[[Selaginella poulteri]]''
* ''[[Selaginella pulcherrima]]''
* ''[[Selaginella rupestris]]'' – rock spikemoss, festoon pine, and northern Selaginella (eastern North America)
* ''[[Selaginella rupincola]]'' <small>Underw.</small> – west Texas to Arizona and Sonora, Mexico
* ''[[Selaginella selaginoides]]'' – lesser clubmoss; north temperate [[Europe]], [[Asia]] and [[North America]])
* ''[[Selaginella sericea]]'' <small>[[A.Braun]]</small> – [[Ecuador]]
* ''[[Selaginella serpens]]''
* ''[[Selaginella sibirica]]''
* ''[[Selaginella stellata]]'' – starry spikemoss; Mexico, [[Central America]]
* ''[[Selaginella substipitata]]''
* ''[[Selaginella tamariscina]]''
* ''[[Selaginella tortipila]]''
* ''[[Selaginella uliginosa]]'' – [[Australia]]
* ''[[Selaginella umbrosa]]''
* ''[[Selaginella uncinata]]'' – peacock moss, peacock spikemoss, blue spikemoss
* ''[[Selaginella underwoodii]]'' <small>Hieron.</small> – west Texas to Wyoming and west into Arizona
* ''[[Selaginella wallacei]]''
* ''[[Selaginella watsonii]]''
* ''[[Selaginella willdenowii]]'' – Willdenow's spikemoss, peacock fern; southeast Asia

A few species of ''Selaginella'' are [[desert]] 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 [[fern]]s.

== Cultivation ==
{{Unreferenced section|date=April 2021}}
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 ==
{{Reflist|2}}

== External links ==
* {{Commons category-inline|Selaginella|''Selaginella''}}
* {{Wikispecies-inline|Selaginella|''Selaginella''}}

{{Plant classification}}
{{Fern classification}}
{{Taxonbar|from=Q379743}}
{{Authority control}}

[[Category:Selaginella| ]]
[[Category:Lycophyte genera]]