A new genus of Lindsaeoid ferns

In revising the New World representatives of the genus Lindsaea, the author came across a fern specimen from Borneo preserved in the Rijksherbarium, Leiden, that did not seem to fit into any described genus. It had been described as Schizoloma stortii v. A. v. R., but in the author’s opinion the genus Schizoloma Gaud., typified by Lindsaea ensifolia Sw., cannot be maintained (Kramer, 1957). Almost all species that in modern works have been left in it (e.g. HOLTTUM, 1954; ALSTON, 1956, as Schizolegnia) should be put back in Lindsaea. This, however, cannot be done with Sch. stortii, as this species possesses a peculiar combination of characters unlike anything found in Lindsaea. Its pinnae have a median main vein as in L. ensifolia, but are freeveined, and they have a large basal acroscopic auricle as in Isoloma, but are non-articulate. There is a remote resemblance to Lindsaea walkerae Hook., which may be its closest relative, as stipulated by van ALDERWEREKT van ROSENBURGH in his original description; the natural place of that species too would perhaps be in a separate genus. Sch. stortii differs from it, a.o., by its pale axes and alternate auriculate pinnae. Because of its apparently rather isolated position, it seems indicated to create a separate genus for this fern. Xyropteris Kramer, genus novum. — Ex affinitate Lindsaeae et Isolomae, exstat petiolo rhachideque pallida, pinnis alternis exarticulatis praeter auriculam basalim acroscopicam aequilateralibus, venis liberis, soris continuis. (Name derived from Greek ξνρόν, razor-blade).