Ptilocladia glandifera Huisman

Scientific Description

Habit and structure. Thallus to 12 mm tall, light pink, spongy, generally with a coating of sand and other particulate matter, attached by rhizoids from lower axial cells, essentially complanately and alternately branched every (3–) 4 (–5) cells; branches 300–500 μm wide. Indeterminate lateral branches arising from the basal cell of a whorl branch, but this origin subsequently obscured and the branch appearing to develop from the axial cell. Each axial cell bearing 4 whorl branches near the distal end, these initially perpendicular to the bearing axis but curving distally and forming a complete covering, 6 or 7 cells long and divaricately dichotomously to trichotomously branched 6 or 7 times. Cells of primary axes to 25 μm diam. near apices [L:B c. 1.2], becoming broader and more elongate in the mid-region, to 50–70 μm diam. [L:B c. 2], then equidimensional near the base, to 125 μm diam. Basal cells of whorl branches to 25 μm diam., tapering to 5–6 μm diam. near the apex [all cells L:B 1–2]. Vesicular cells arising on apical and subapical cells of whorl branches, pyriform, obovoid or subspherical, 25–32 μm long and 12–25 μm diam. Cells with numerous ribbon shaped plastids. Carpogonial branches 4-celled, curved, developing on a periaxial supporting cell near the apices of primary axes. Carposporophytes subspherical, to 350 μm diam., composed entirely of carposporangia 35–60 μm diam.

Reproduction. Tetrasporangia on basal and suprabasal cells of whorl branches, subspherical, 45–80 μm diam., including a wall 7–8 μm thick, tetrahedrally divided.

Distribution. Known from Kendrew Is., Dampier Archipelago and Barrow Is., Western Australia.

[After J.M. Huisman in Algae of Australia: Marine Benthic Algae of North-western Australia, 2. Red Algae: 367–369 (2018)]