A new genus of pleridosperms is described from the uppermost Devonian beds from Ballyheigue, Ireland.I.aceya hibernicaMay&Mat ten is represented by stems bearing spirally arranged fronds. The base of the frond is swollen and is about the same size as the stem. Pinnae are borne alternately and apparently in one plane on the rachis. The anatomy of the stem reveals a three‐fluted protostele. Secondary xylem consists of rays and trachcids and secondary phloem is present. The inner cortex contains probable secretory and/or sclerotic cells. The outer cortex is of the spargaimm‐type. Rachial trace formation is described. The U‐shaped xylem strand of the rachis lacks secondary tissue. Pinnae traces are V‐ to C‐shaped. A presumed adventitious root has a triarch protostele, a parenchymatous cortex and lacks a ‘sparganum’ outer zone.I.aceyais believed to be a member of the Lyginopleridaceae. The divisions of the sympodial protoxylem strand forming the rachial trace is compared among the Aneurophytales, Buteoxylonaceae, Calamopityaceae and Lyginopteridaceae and is shown