Anadyomene wrightii J.E.Gray

Scientific Description

Habit and structure. Thallus yellowish-green to dark green, firm, flabellate, to 15 mm in height and  20 mm broad. Holdfast a mass of rhizoidal cells, these only occasionally septate. Primary filaments polychotomously branched, with most branches at each node becoming prominent; cells of primary filaments near apices clavate and 50–75 µm in diameter, becoming cylindrical below and 100–150 µm in diameter, dividing transversely several times to produce series of 12–16 cells between nodes, these with L:B 1–2. Some cells of primary filaments, particularly near base of plant, remaining undivided and therefore elongate. Interstitial cells between axial filaments in 1–2 layers. Secondary cortication of veins absent or only slight near base, the primary axes remaining clearly visible.