Carpopeltis phyllophora (Hook.f. & Harv.) F.Schmitz

Scientific Description

Habit and structure. Thallus dark red-brown, cartilaginous, 4–25 cm high, complanately and alternately branched, upper branches 2–4 mm broad in small forms, 3–5 mm broad in robust forms, 80–120 µm thick above, 150–200 µm thick below, apices broad and rounded, axils usually rounded, becoming denuded below with a thickened midrib. Holdfast discoid, 1–5 mm across; epilithic. Structure of a pseudoparenchymatous cortex 4–8 cells thick, outer cells 2–4 µm across, slightly elongate in section, inner cells subspherical to ovoid, 10–15 µm across, stellate cells absent. Medulla relatively thin (one third to one sixth of the thickness of thallus), of densely entwined filaments; refractive ganglionic cells absent. Rhodoplasts discoid to elongate, several per cell.

Reproduction. Sexual thalli monoecious, with sexual organs in separate sori in terminal branches. Carpogonial branch ampullae with a few (4–6) simple or once branched secondary filaments and a 2-celled carpogonial branch with the trichogyne reflexed just outside the thallus surface. Auxiliary cell ampullae with numerous elongate, simple or once branched secondary filaments extending almost to and sometimes through the thallus surface, converging above. Carposporophytes clustered in thickened branch ends (300–500 µm thick), with a fairly prominent involucre, ostiolate. Spermatangia in sori, cut off from outer cortical cells, 1.5–2.5 µm in diameter. Tetrasporangia in nemathecia near ends of branches 200–250 µm thick, amongst paraphyses 3–5 cells long and 2–3 µm in diameter, 15–30 µm long and 6–9 µm in diameter, cruciately divided.

Distribution.Geraldton, W. Aust., to Phillip I., Vic., and around Tas.

Habitat. C. phyllophora occurs on rough-water coasts from shaded shallow situations to 37 m deep.

[After Womersley, Mar. Benthic Fl. Southern Australia IIIA: 169–170 (1994)]