Editing Lycopodiopsida (section)

===Classification===
The rank and name used for the taxon holding the extant lycophytes (and their closest extinct relatives) varies widely. Table 1 below shows some of the highest ranks that have been used. Systems may use taxa at a rank lower than the highest given in the table with the same circumscription; for example, a system that uses Lycopodiophyta as the highest ranked taxon may place all of its members in a single subclass.
{{anchor|Table 1}}
{| class="wikitable"
|+ Table 1: Alternative highest ranks used which include only extant species and their closest relatives
|-
! Highest rank !! Name !! Example sources
|-
| Division (phylum)|| Lycophyta || Taylor et al. (2009),<ref name=TaylTaylKrin09/> Mauseth (2014)<ref name=Maus14/>
|-
| Division (phylum) || Lycopodiophyta || Niklas (2016)<ref name=Nikl16/>
|-
| Subdivision (subphylum)|| Lycopodiophytina || Ruggiero et al. (2015)<ref name=RuggGordOrreBail15/>
|-
| Class || Lycopsida || Kenrick & Crane (1997)<ref name=KenrCran97a/><ref name=KenrCran97b/>
|-
| '''Class''' || '''Lycopodiopsida''' || PPG I (2016)<ref name=PPGI/>
|-
| Subclass || Lycopodiidae || Chase & Reveal (2009)<ref name=ChasReve09/>
|}

Some systems use a higher rank for a more broadly defined taxon of lycophytes that includes some extinct groups more distantly related to extant lycophytes, such as the [[zosterophyll]]s. For example, Kenrick & Crane (1997) use the subdivision Lycophytina for this purpose, with all extant lycophytes falling within the class Lycopsida.<ref name=KenrCran97a/> Other sources exclude the zosterophylls from any "lycophyte" taxon.<ref name=TaylTaylKrin09/>

In the [[Pteridophyte Phylogeny Group]] classification of 2016 (PPG I), the three orders are placed in a single class, Lycopodiopsida, holding all extant lycophyte species. Older systems have used either three classes, one for each order, or two classes, recognizing the closer relationship between Isoetales and Selaginellales. In these cases, a higher ranked taxon is needed to contain the classes (see Table 1). As Table 2 shows, the names "Lycopodiopsida" and "Isoetopsida" are both ambiguous.
{{anchor|Table 2}}
{| class="wikitable"
|+ Table 2: Alternative arrangements of the orders of extant lycophytes into classes
|-
! Order || 3 classes<br/>e.g. ''IUCN Red List'', 2004<ref name=BailHiltStua04/> || 2 classes<br/>e.g. Yatsentyuk et al. (2001)<ref name=Yats01/> || 1 class<br/>PPG I<ref name=PPGI/>
|-
| Lycopodiales || Lycopodiopsida || Lycopodiopsida ||rowspan=3|Lycopodiopsida
|-
| Isoetales || |Isoetopsida ||rowspan=2|Isoetopsida
|-
| Selaginellales || Sellaginellopsida
|}