The morphology and taxonomy of Womersleya monanthos, an endemic species and genus of Delesseriaceae (Ceramiales, Rhodophyta) from southeastern Australia

Abstract

SUMMARY Womersleya monanthos (J. Agardh) Papenfuss is typically an epiphyte of larger brown and red algae that are common in drift along the southeastern coasts of Australia. A hitherto little‐known member of the Phycodrys group of the Nitophylloideae, its reproductive features have been studied in detail and its taxonomic position clarified. Blades are polystromatic throughout and lack veins or nerves, with blades originating from apical cells of primary and second‐order cell rows. Intercalary cell divisions take place in primary cell rows and all other branch orders, with third‐order laterals arising both abaxially and adaxially on cells of second‐order rows. Fertile central cells bear procarps on pericentral cells on both sides of the blade, the procarps consisting of two 4‐celled carpogonial branches and a single central group of sterile cells that enlarge and persist at the distal end of a bicampanulate fusion cell at maturity. Spermatangia and tetrasporangia form in circular subapical sori on both sides of the blade or in marginal lobes or proliferations. After comparing it to other members of the Phycodrys group, we conclude that Womersleya is a monotypic genus well distinguished from other genera and with probable closest affinities to the Northern Hemisphere Polyneura, Erythroglossum and Sorella, as well as the Australian endemic, Crassilingua.