Wikipedia
Crenaticaulis
Crenaticaulis was an early genus of slender, dichotomously branching, leafless land plants, known from the Devonian period and first described in 1969. They were probably allied to the zosterophylls, and are assigned to subdivision Zosterophyllophytina, or class Zosterophyllopsida. They bore branches and scalariform tracheids.
A cladogram published in 2004 by Crane et al. places Crenaticaulis in the core of a paraphyletic stem group of broadly defined " zosterophylls", basal to the lycopsids (living and extinct clubmosses and relatives).