Lycopodiaceae

Members of Lycopodiaceae are not spermatophytes and so do not produce seeds. Instead they produce spores, which are oily and flammable, and are the most economically important aspects of these plants. The spores are of one size (i.e. the plants are isosporous) and are borne on a specialized structure at the apex of a shoot called a strobilus (plural: strobili), which resembles a tiny battle club, from which the common name derives. Members of the family share the common feature of having a microphyll, which is a "small leaf with a single vein, and not associated with a leaf gap in the central vascular system." In Lycopodiaceae, the microphylls often densely cover the stem in a linear, scale-like, or appressed fashion to the stem, and the leaves are either opposite or spirally arranged. The club mosses commonly grow to be 5–20 cm tall. The gametophytes

in most species are non-photosynthetic and myco-heterotrophic, but the subfamily Lycopodielloideae and a few species in the subfamily Huperzioideae have gametophytes with an upper green and photosynthetic part, and a colorless lower part in contact with fungal hyphae.[https://books.google.com/books?id=AX8OH-k1PmUC&dq=Huperzia+Lycopodiella+gametophyte+mycoheterotrophic&pg=PA26 Mycoheterotrophy: The Biology of Plants Living on Fungi][https://teses.usp.br/teses/disponiveis/41/41132/tde-18052017-150806/publico/DaniloSoares_Gissi.pdf Phylogeny of Phlegmariurus (Lycopodiaceae) focusing on Brazilian endemic species] In Lycopodioideae monoplastidic meiosis is common, whereas polyplastidic meiosis is found in Lycopodielloideae and Huperzioideae.[https://revistas.ucr.ac.cr/index.php/rbt/article/view/12330 Sporogenesis, sporoderm and mature spore ornamentation in Lycopodiaceae]

The family Lycopodiaceae is considered to be basal within the Lycopodiopsida (lycophytes). One hypothesis for the evolutionary relationships involved is shown in the cladogram below.

{{clade

|label1=Lycopodiopsida

|1={{clade

|1=Lycopodiaceae

|2={{clade

|1=Isoetaceae

|2=Selaginellaceae

}}

}}

}}

Within the family, there is support for three subgroups. In 2016, Field et al. proposed that the primary division is between Lycopodielloideae plus Lycopodioideae and the Huperzioideae (names sensu PPG I).{{Cite journal|last=Field|display-authors=etal|date=January 2016|title=Molecular Phylogenetics and the Morphology of the Lycopodiaceae Subfamily Huperzioideae Supports Three Genera: Huperzia, Phlegmariurus and Phylloglossum|journal=Molecular Phylogenetics and Evolution|volume=94, Part B|issue=Pt B|pages=635–57|doi=10.1016/j.ympev.2015.09.024|pmid=26493224}}

{{clade

|label1=Lycopodiaceae

|1={{clade

|1={{clade

|1=Lycopodielloideae (Lycopodiella s.l.)

|2=Lycopodioideae (Lycopodium s.l.)

}}

|2=Huperzioideae (Huperzia s.l.)

}}

}}

There are about 400 known species in the family Lycopodiaceae. Sources differ in how they group these into genera. Field et al. (2016) say "Most Lycopodiaceae species have been re-classified into different genera several times, leading to uncertainty about their most appropriate generic identification." In the PPG I system, the family has 16 accepted genera, grouped into three subfamilies, Lycopodielloideae, Lycopodioideae and Huperzioideae, based in part on molecular phylogenetic studies. The Huperzioideae differ in producing spores in small lateral structures in the leaf axils, and it has been suggested that they be recognized as a separate family.{{citation needed|date=October 2019}} Other sources use fewer genera; for example, the three genera placed in the subfamily Huperzioideae in PPG I, Huperzia, Phlegmariurus and Phylloglossum, have also all been treated within a broadly defined Huperzia.

The species within this family generally have chromosome counts of n=34. A notable exception are the species in Diphasiastrum, which have counts of n=23.[http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=110327 Flora of North America, Diphasiastrum]

{{As of|2024|June}}, the Checklist of Ferns and Lycophytes of the World recognized the following genera as members of Lycopodiaceae. All of these are recognized by the Pteridophyte Phylogeny Group classification of 2016 (PPG I), except for the genus Brownseya, described in 2021. Other classifications circumscribe the genera in the family more broadly, recognizing the subfamilies Lycopodielloideae, Lycopodioideae, and Huperzioideae as the genera Lycopodiella, Lycopodium, and Huperzia.

Phylogeny of Lycopodiaceae{{Citation |last1=Chen |first1=De-Kui |last2=Zhou |first2=Xin-Mao |last3=Rothfels |first3=Carl J. |last4=Shepherd |first4=Lara D. |last5=Knapp |first5=Ralf |last6=Zhang |first6=Liang |last7=Lu |first7=Ngan Thi |last8=Fan |first8=Xue-Ping |last9=Wan |first9=Xia |last10=Gao |first10=Xin-Fen |last11=He |first11=Hai |last12=Zhang |first12=Li-Bing |year=2021 |title=A global phylogeny of Lycopodiaceae (Lycopodiales; lycophytes) with the description of a new genus, Brownseya, from Oceania |journal=Taxon |volume=71 |issue=1 |pages=25-51 |doi=10.1002/tax.12597 |doi-access=free |url=https://onlinelibrary.wiley.com/doi/abs/10.1002/tax.12597|url-access=subscription }}{{Citation |last1=Chen |first1=De-Kui |last2=Zhou |first2=Xin-Mao |last3=Rothfels |first3=Carl J. |last4=Shepherd |first4=Lara D. |last5=Knapp |first5=Ralf |last6=Zhang |first6=Liang |last7=Lu |first7=Ngan Thi |last8=Fan |first8=Xue-Ping |last9=Wan |first9=Xia |last10=Gao |first10=Xin-Fen |last11=He |first11=Hai |last12=Zhang |first12=Li-Bing |year=2021 |title=Fig. S1 Maximum likelihood phylogeny of Lycopodiaceae based on seven plastid markers (atpA, psbA-trnH, rbcL, rps4 & rps4-trnS, trnL & trnL-F) |journal=Taxon |volume=71 |issue=1 |pages=25-51 |doi=10.1002/tax.12597 |doi-access=free |url=https://onlinelibrary.wiley.com/action/downloadSupplement?doi=10.1002%2Ftax.12597&file=tax12597-sup-0002-FigureS1.pdf}}

{{clade| style=font-size:100%;line-height:90%;width:600px;

|label1=Lycopodiaceae

|1={{clade

|1={{clade

|label1=Huperzioideae

|sublabel1=Wagner & Beitel ex Øllgaard

|1={{clade

|1=Huperzia s.s. Bernhardi

|2={{clade

|1=Phylloglossum Kunze

|2=Phlegmariurus (Herter) Holub

}}

}}

}}

|2={{clade

|1={{clade

|label1=Lycopodielloideae

|sublabel1=Wagner & Beitel ex Øllgaard

|1={{clade

|1={{clade

|1={{clade

|1=Brownseya Zhang et al.

|2=Palhinhaea Franco & Vasconcellos

}}

|2=Lateristachys Holub

}}

|2={{clade

|1=Pseudolycopodiella Holub

|2=Lycopodiella Holub

}}

}}

}}

|2={{clade

|label1=Lycopodiastroideae

|sublabel1=Zhang & Zhou

|1=Lycopodiastrum Holub ex Dixit

|label2=Lycopodioideae

|sublabel2=Eaton ex Øllgaard

|2={{clade

|1={{clade

|1=Diphasiastrum Holub

|2={{clade

|1=Lycopodium s.s. von Linné

|2=Spinulum Haines

}}

}}

|2={{clade

|1={{clade

|1=Pseudolycopodium Preslia ex Holub

|2={{clade

|1=Pseudodiphasium Holub

|2=Austrolycopodium Holub

}}

}}

|2={{clade

|1=Dendrolycopodium Haines

|2=Diphasium Presl ex Rothmaler

}}

}}

}}

}}

}}

}}

}}

The members of Lycopodiaceae are terrestrial or epiphytic in habit and are most prevalent in tropical mountain and alpine environments. Though Lycopodiaceae are most abundant in these regions, they are cosmopolitan, excluding arid environments.{{Cite book|last=Øllgaard|first=B.|chapter=Lycopodiaceae |date=1990|title=Pteridophytes and Gymnosperms|journal=In Pteridophytes and Gymnosperms|pages=31–39|doi=10.1007/978-3-662-02604-5_10|isbn=978-3-642-08080-7}}

Lycopodiaceae (homosporous lycophytes) split off from the branch leading to Selaginella and Isoetes (heterosporous lycophytes) about ~400 million years ago, during the early Devonian. The two subfamilies Lycopodioideae and Huperzioideae diverged ~350 million years ago, but has evolved so slowly that about 30% of their genes are still in syntenic blocks (remaining in the same arrangement). They have also gone through independent whole genome duplications. In most plants the majority of duplicate genes are lost relatively quickly through diploidization, but in this group both sets of genes tends to be retained with relatively few alterations, even after hundreds of millions of years after the duplication event.[https://phys.org/news/2024-01-window-evolution-unusual-genetic-journey.html A window into plant evolution: The unusual genetic journey of lycophytes][https://www.pnas.org/doi/10.1073/pnas.2312607121 Extraordinary preservation of gene collinearity over three hundred million years revealed in homosporous lycophytes] Spores indicate that the crown group of Lycopodiaceae had emerged by the Triassic-Jurassic boundary, around 200 million years ago,{{Cite journal |last1=Wikström |first1=Niklas |last2=Larsén |first2=Eva |last3=Khodabandeh |first3=Anbar |last4=Rydin |first4=Catarina |date=January 2023 |title=No phylogenomic support for a Cenozoic origin of the "living fossil" Isoetes |journal=American Journal of Botany |language=en |volume=110 |issue=1 |pages=e16108 |doi=10.1002/ajb2.16108 |issn=0002-9122 |pmc=10108322 |pmid=36401556}} with a member of the crown group of Lycopodioideae known from the Early Cretaceous of China.{{Cite journal |last1=Herrera |first1=Fabiany |last2=Testo |first2=Weston L. |last3=Field |first3=Ashley R. |last4=Clark |first4=Elizabeth G. |last5=Herendeen |first5=Patrick S. |last6=Crane |first6=Peter R. |last7=Shi |first7=Gongle |date=March 2022 |title=A permineralized Early Cretaceous lycopsid from China and the evolution of crown clubmosses |journal=New Phytologist |language=en |volume=233 |issue=5 |pages=2310–2322 |doi=10.1111/nph.17874 |issn=0028-646X |pmid=34981832 |s2cid=245670357|doi-access=free }}

• The running clubmosses (Diphasiastrum) have long been used as greenery for Christmas decoration.
• The spores have long been used as a flash powder. See Lycopodium powder.
• The spores have been used by violin makers for centuries as a pore filler.
• In Cornwall, club mosses gathered during certain lunar phases were historically used as a remedy for eye disease.

{{Reflist|refs=

{{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 | publisher = Magnolia Press | doi-access = free }}

{{cite WF |taxon=Lycopodiaceae |access-date=2024-06-02}}

{{cite journal | last1 = PPG | first1 = I | year = 2016 | title = A community-derived classification for extant lycophytes and ferns | journal = Journal of Systematics and Evolution | volume = 54 | issue = 6| pages = 563–603 | doi = 10.1111/jse.12229 | s2cid = 39980610 | doi-access = free }}

}}

{{Wikispecies}}

{{Commons category|Lycopodiaceae}}

• {{cite book

| last =Thiselton-Dyer

| first =Thomas F.

| title =The Folk-lore of Plants

| year =1889

| url =https://www.gutenberg.org/ebooks/10118

}}

• {{cite journal | last1 = Wagner | first1 = W. H. Jr. | last2 = Beitel | first2 = J. M. | year = 1992 | title = Generic classification of modern North American Lycopodiaceae | url =https://www.biodiversitylibrary.org/part/26770 | journal = Ann. Missouri Bot. Gard. | volume = 79 | issue = 3| pages = 676–686 | doi=10.2307/2399759| jstor = 2399759 }}
• [http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=10527 Lycopodiaceae] in Flora of North America

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Category:Plant families