What is "hedeia"

Hedeia is a genus of early land plants of uncertain affinity. It comprises erect axes terminating in corymbose clusters of erect sporangia. Cookson gave no derivation of the generic name.

The type species, H. corymbosa, was first described by Isabel Cookson from a few specimens in fine sandstone from near Alexandra, Victoria, Australia. At the time, the locality was regarded as being of Silurian age, but it is now known to be Early Devonian. It is claimed that an undescribed species, also from Victoria, extends from the Early Devonian back to the Late Silurian.

H. parvula from Kazakhstan and H. sinica from China are also of Early Devonian age.

It is sometimes suggested that Hedeia and Yarravia are merely different preservations of the same type of plant.