Pleuromeiaceae is an extinct family of plants related to living quillworts (''

Isoetes ''Isoetes'', commonly known as the quillworts, is the only extant genus of plants in the family Isoetaceae, which is in the class of lycopods. There are currently 192 recognized species, with a cosmopolitan distribution but with the individual sp ...

''), in the order

Isoetales Isoetales, sometimes also written Isoëtales, is an order of plants in the class Lycopodiopsida. There are about 140-150 living species, all of which are classified in the genus ''Isoetes'' (quillworts), with a cosmopolitan distribution, but o ...

but with tall stems and terminal compact cones. They were especially widespread globally during the Early and Middle Triassic in the aftermath of the Permian-Triassic mass extinction.

References

Prehistoric plant families Prehistoric lycophytes {{paleo-lycophyte-stub