Valeriemayagen. nov. (Rhodophyta), with a discussion of apical organizations within the Delesseriaceae

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Abstract
Valeriemaya gen. nov. is described from subtidal habitats along the New South Wales coast of eastern Australia and assigned to the red algal family Delesseriaceae. Valeriemaya geminata sp. nov., designated the generitype, and V. maculata sp. nov. are assigned to this genus. Plants in both species form a small component of the turf community of the rocky reef flora, occurring from the lowest littoral to a death of 20 m. They consist of clusters of mostly simple, lanceolate blades arising from holdfasts that may be discoid or well-developed, spreading systems of terete, branched axes firmly clasped to the substratum. V. geminata is distinctive in having a pair of ovate tetrasporangial sori mid-way along the erect blades, a habit in which erect blades recurve toward the substratum, attaching by means of rhizoidal tufts and producing new blades, and in its lack of vesicular cells, whereas V. maculata is distinctive in having single, large, ovate, tetrasporangial sori located at the bases of the blades, a habit in which the erect blades do not become attached to the substratum at their distal ends, and in having prominent vesicular cells. Sexual plants are described for V. geminata. The scattered nature of the procarps shows that the genus belongs in the Nitophylloideae. Male plants bear spermatangial sori in irregular rectangular patches separated by sterile cells. The apices are diagnostic in having single, transversely divided apical cells and second-order cell rows producing third-order cell rows adaxially. The apical organization in this species closely resembles that in certain other taxa of this family which had previously been allied with the Phycodrys and Pollexfenia groups of Nitophylloideae. Evidence is presented to support the delineation of a new type of apical organization (the Valeriemaya-type) which warrants its own group (the Valeriemaya group) and which is distinguishable from that of the Phycodrys group.