# Lycopodiaceae systematics and classification

**Lycopodiaceae** is a family of vascular plants, the clubmosses and firmosses, placed in the class [Lycopodiopsida](https://www.edgepedia.org/lycopodiopsida) and order [Lycopodiales](https://www.edgepedia.org/lycopodiales). It contains about 400 species distributed on all continents except [Antarctica](https://www.edgepedia.org/antarctica), with its highest diversity in tropical regions.<sup>[1](https://onlinelibrary.wiley.com/doi/10.1002/tax.12597)</sup> The family is one of the oldest lineages of living vascular plants; a divergence-time analysis estimates its crown age at 368.4 million years ago (95% highest posterior density 326–389 Ma), in the Devonian.<sup>[2](https://www.uvm.edu/~dbarring/publications/testo2018-2.pdf)</sup> This article covers how the family has been delimited, its current subfamilies and genera, and the segregation of genera from the historically broad genus *Lycopodium*.

| Key fact | Detail |
| --- | --- |
| Family | Lycopodiaceae P.Beauv. ex Mirb., 1802<sup>[3](https://ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&id=3250)</sup> |
| Species | About 400, on all continents except Antarctica<sup>[1](https://onlinelibrary.wiley.com/doi/10.1002/tax.12597)</sup> |
| Genera | 17 in the 2021 global phylogeny; 16 in PPG I (2016)<sup>[1](https://onlinelibrary.wiley.com/doi/10.1002/tax.12597)</sup> |
| Subfamilies | Huperzioideae, Lycopodioideae, Lycopodielloideae<sup>[1](https://onlinelibrary.wiley.com/doi/10.1002/tax.12597)</sup> |
| Crown age | 368.4 Ma (95% HPD 326–389 Ma)<sup>[2](https://www.uvm.edu/~dbarring/publications/testo2018-2.pdf)</sup> |
| Synonyms | Huperziaceae, Phylloglossaceae (per ITIS)<sup>[4](https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=17012)</sup> |

## Historical delimitation and Huperziaceae

Circumscription of the family has varied among classifications. Some authors have recognized a separate family, Huperziaceae, for the firmoss group, and ITIS lists Huperziaceae and Phylloglossaceae as synonyms of Lycopodiaceae, reflecting treatments in which these groups were split off.<sup>[4](https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=17012)</sup> In the PPG I classification of 2016, produced by the Pteridophyte Phylogeny Group, the Huperzioideae are retained within Lycopodiaceae.

The Flora of the [Southeastern United States](https://www.edgepedia.org/southeastern-united-states) describes the family as containing 10 to 15 genera and about 400 species, and follows PPG I (2016) for its generic taxonomy.<sup>[5](https://fsus.ncbg.unc.edu/main.php?exactmatch=yes&pg=show-taxon.php&plantname=Lycopodiaceae)</sup>

## Subfamilies and phylogeny

Molecular phylogenetic studies support three subfamilies within Lycopodiaceae: Lycopodielloideae, Lycopodioideae, and Huperzioideae.<sup>[6](https://doi.org/10.1002/tax.12597)</sup> A global phylogeny published in *Taxon*, based on 1150 DNA sequences from 334 accessions representing around 155 species, resolved the family into three primary clades corresponding to these three subfamilies.<sup>[1](https://onlinelibrary.wiley.com/doi/10.1002/tax.12597)</sup> An earlier analysis by Field et al.

The divergence-time study gives dates for the main splits: the divergence of Lycopodioideae and Lycopodielloideae is estimated at 293.6 Ma (95% HPD 262–320 Ma), and the crown age of Huperzioideae at 199.5 Ma (95% HPD 175–223 Ma), near the Triassic-Jurassic boundary.<sup>[2](https://www.uvm.edu/~dbarring/publications/testo2018-2.pdf)</sup> Fossil evidence, the Lower Jurassic stem section *Lycoxylon indicum*, indicates a minimum age of 208 Mya for the split between [Lycopodium](https://www.edgepedia.org/lycopodium) and [Lycopodiella](https://www.edgepedia.org/lycopodiella), which is consistent with the older node-dating estimate for the subfamily divergence.<sup>[5](https://fsus.ncbg.unc.edu/main.php?exactmatch=yes&pg=show-taxon.php&plantname=Lycopodiaceae)</sup>

## Genera and the breakup of Lycopodium

Historically, most clubmoss species were placed in a broadly defined *Lycopodium*. Successive segregations split this genus into many smaller ones, and, as Field et al. (2016) noted, most Lycopodiaceae species have been re-classified into different genera several times, leading to uncertainty about their most appropriate generic identification.<sup>[7](https://onlinelibrary.wiley.com/doi/full/10.1111/jse.12229)</sup>

The 2021 global phylogeny recognized 17 genera in the three subfamilies and described a new genus, Brownseya, for *Lycopodiella serpentina*, previously placed in *Lycopodiella*.<sup>[1](https://onlinelibrary.wiley.com/doi/10.1002/tax.12597)</sup> The same study found *Huperzia*, *Lycopodiella*, *Pseudolycopodiella*, and *Spinulum* each strongly supported as monophyletic (a group containing all descendants of one common ancestor), and *Phylloglossum* as sister to *Phlegmariurus*.<sup>[1](https://onlinelibrary.wiley.com/doi/10.1002/tax.12597)</sup>

- **Lycopodielloideae:** Brownseya, Lateristachys, Lycopodiella, Palhinhaea, Pseudolycopodiella
- **Lycopodioideae:** Austrolycopodium, Dendrolycopodium, Diphasiastrum, Diphasium, Lycopodiastrum, Lycopodium, Pseudodiphasium, Pseudolycopodium, Spinulum
- **Huperzioideae:** Huperzia, Phlegmariurus, Phylloglossum

## Chromosome numbers

Chromosome base numbers vary substantially across the family. The Flora of the Southeastern United States lists x=23 for *Diphasiastrum*, x=34 for *Dendrolycopodium* and *Lycopodium*, x=67 and 68 for *Huperzia*, x=78 for *Lycopodiella*, and x=55 for *Palhinhaea*.<sup>[5](https://fsus.ncbg.unc.edu/main.php?exactmatch=yes&pg=show-taxon.php&plantname=Lycopodiaceae)</sup>

## References

1. [A global phylogeny of Lycopodiaceae (Lycopodiales; lycophytes) with the description of a new genus, Brownseya, from Oceania](https://onlinelibrary.wiley.com/doi/10.1002/tax.12597), *Taxon*.
2. [Overcoming among-lineage rate heterogeneity to infer the divergence times and biogeography of the clubmoss family Lycopodiaceae](https://www.uvm.edu/~dbarring/publications/testo2018-2.pdf).
3. [NCBI Taxonomy Browser: Lycopodiaceae](https://ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&id=3250).
4. [ITIS Report: Lycopodiaceae](https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=17012).
5. [Lycopodiaceae (Clubmoss Family), Flora of the Southeastern United States](https://fsus.ncbg.unc.edu/main.php?exactmatch=yes&pg=show-taxon.php&plantname=Lycopodiaceae).
6. [A global phylogeny of Lycopodiaceae (Lycopodiales; lycophytes) with the description of a new genus, Brownseya , from Oceania, doi.org](https://doi.org/10.1002/tax.12597)
7. [A community‐derived classification for extant lycophytes and ferns - - 2016 - Journal of Systematics and Evolution - Wiley Online Library, onlinelibrary.wiley.com](https://onlinelibrary.wiley.com/doi/full/10.1111/jse.12229)

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*Topic: Encyclopedia › Life and health › Plants and algae › Ferns and lycophytes › Fern allies: lycophytes and horsetails › Lycophytes › Clubmosses (Lycopodiaceae) › Lycopodiaceae systematics and classification*

*Initially written Sep 17, 2026 · Reviewed: Sep 30, 2026 · Edited: Sep 30, 2026; Oct 25, 2026 · Last review: Sep 30, 2026*

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