Spyridia hypnoides (Bory de Saint- Vincent) Papenfuss, 1968

    Thallus erect, robust and densely branched, composed of percurrent, plumose axes, attached by means of a conspicuous stupose holdfast to 1.5 cm in diameter, brownish-red with orangy apices; axes completely corticated up to immediately below the apices, ca 2 mm in diameter in the proximal parts, spirally branched, every segment producing a determinate lateral at 60° angles; determinate laterals straight, 300-900 μm long, proximally 150-280 μm in diameter, gradually tapering toward the apices, terminating in a single erect spine subtended by a variable number (2-5) of recurved spines on subterminal cells. Internal structure of the axes composed of a central axial filament and whorls of (12-) 14-15 (-17) periaxial cells which give rise to 2 basipetal cortical filaments each; primary cortex obscured by secondary cortical cells; determinate branchlets with a smaller number of periaxial cells (6-8) and only just becoming completely corticated, always with the initial cortical bands readily discernable. Tetrasporangia on proximal segments of determinate laterals, sessile, 1-4 per central cell and completely exposed, measuring 39-68 µm diameter.