Dictyopteris delicatula J.V.Lamour.

Scientific Description

Habit and structure. Thalli epiphytic and on rocky substrata, usually sprawling and only distally erect, often a component of low algal turfs, light to medium chocolate-brown, 2–5 cm long, 1–2 mm wide; branching both dichotomous and cervicorn or commonly pseudomonopodial in mature fronds, strictly dichotomous when juvenile. Attachment basally, apically and marginally by clusters of adventitious rhizoids. Thalli distromatic, 90–100 µm thick at the margins, becoming 4-celled and up to 110 µm thick submarginally where a single longitudinal vein of 3 or 4 thickened cells runs parallel to the long axis of the blade. Midrib 6–8 cells and 160–200 µm thick, the walls of interior cells, like those of the submarginal veins, substantially thickened. Cells of the wings 20–40 µm long, 20–40 µm wide and 30–50 µm tall.

Reproduction. Most collections were sterile, although a few thalli in May samples from Neds Beach appeared to have rounded juvenile sporangia clustered near branch tips.

Distribution. Almost pantropical, although one of the few widespread tropical species not yet recorded from the Hawaiian Islands. In Australia, known from W. Aust., north and east to Qld., and south to Lord Howe I. and the mainland of N.S.W.

[After Kraft, Algae of Australia: Marine Benthic Algae of Lord Howe Island and the Southern Great Barrier Reef, 2: Brown Algae:144–147 (2009)]