Martensia millarii Showe M.Lin & Huisman

Scientific Description

Habit and structure. Thalli light pink to dark red, to 7–13 cm tall, consisting of 1–3 blades, flabellate, membranous, with an inner entire region bordered by a network comprising approximately 60–90% of the thallus. Blade network composed of primary cross-connecting and longitudinal lamellae that bear needle-like secondary cross-connecting strands. Cells at the base of the network dividing both anticlinally and longitudinally once or twice only. Numerous secondary pit connections formed between cells of the membranous parts of the blades. Gametophytes presumably dioecious, morphologically similar to the tetrasporophytes, with the thallus network up to 11–12 cm long.

Reproduction. Tetrasporangial sori comparatively small, elliptical or oval, 80–150 µm long and 50–60 µm wide, formed on primary longitudinal lamellae scattered over the network except the basal part. Spermatangial sori produced on longitudinal lamellae or special bladelets borne on the cross-connecting strands. Spermatangial parental cell initials cut off from surface cells of longitudinal lamellae or special bladelets, each spermatangial parental cell cutting off 1 or 2 spermatangia.

Distribution. Endemic to north-western Australia.

Habitat. Epilithic in the intertidal and shallow subtidal.

[After J.M. Huisman & S.-M. Lin in Algae of Australia: Marine Benthic Algae of North-western Australia, 2. Red Algae: 468–471 (2018)]