Pertica

Pertica is a genus of extinct vascular plants of the Early to Middle Devonian (around 420 to 380 million years ago).

It has been placed in the "trimerophytes", a strongly paraphyletic group of early members of the lineage leading to modern ferns and seed plants.

[4] Pertica quadrifaria (the type species of the genus) was described in 1972 from compression fossils found in the Trout Valley Formation of northern Maine, USA.

The plant appears to have been similar to P. quadrifaria (only part is known), comprising a central stem (axis) with spirally arranged dichotomous side branches, some of which terminated in erect clusters of between 32 and 128 sporangia.

[2] Consistent with this, a cladogram published in 2004 by Crane et al. places Pertica in a paraphyletic stem group basal to the seed plants (spermatophytes) which have such leaves.