Abstract
Decorticated woody stems from the Tournaisian (early Mississippian) of Montagne Noire, Southern France, are characterized by a wide eustele with a parenchymatous pith and numerous primary xylem strands in contact with the secondary xylem. Primary xylem maturation is endarch to mesarch. Small leaf traces are emitted according to a spiral phyllotaxis. Secondary xylem is dense, composed of tracheids with araucarian pitting, and uni- to triseriate rays that do not exceed 40 cells in height. Anatomy of the primary and secondary vascular system of the Montagne Noire specimens allows their assignment to Eristophyton, an arborescent genus of putative seed plant affinities. However, they display a combination of characters unknown in previously reported species and are assigned to Eristophyton feistii sp. nov. This new species extends both the stratigraphical and geographical range of the genus. Eristophyton feistii contributes to enlarge the taxonomic diversity and anatomical disparity of putative arborescent seed plants occurring soon after the Devonian/Carboniferous boundary.