Morphology and systematics of Calliblepharis hypneoides, sp. nov. (Cystocloniaceae, Rhodophyta) from the Atlantic Iberian Peninsula

Abstract

Calliblepharis hypneoides Díaz-Tapia, Bárbara & Hommersand, sp. nov., is described based on plants collected in sand-covered rocks from southern France to Portugal. Calliblepharis hypneoides is distinguished by a terete thallus, forming an extensive basal system of entangled prostrate axes that bear few irregularly branched upright axes, an inner structure consisting of a central axial filament surrounded by 5–7 filaments of elongated cells, a continuous outer cortex, spermatangial parent cells transformed from outer cortical cells and bearing spermatangial filaments three or four cells long, a single gonimoblast initial cut off from the inner side of the auxiliary cell, with the young carposporophyte consisting of a central reticulate network of interconnected cells linked inwardly to a cluster of basal nutritive filaments and forming gonimoblasts outwardly that bear chains of carposporangia in non-ostiolate cystocarps arising on main axes and branches, and tetrasporangia terminal in sori on ultimate branchlets. These features are characteristic of Calliblepharis and molecular analyses confirm this relationship. In all phylogenetic analyses of cox1, rbcL and SSU sequences, C. hypneoides was consistently distinct from congeners. In both rbcL and SSU trees, its sister relationship to other species was unresolved, probably due to missing species or the exclusion of undescribed species. This is the first report on the systematics of Calliblepharis using three molecular markers.