Calliblepharis planicaulis (Harv.) Kylin

Scientific Description

Habit and structure. Thallus medium red to red-brown, 10–30 cm high, much branched irregularly for 3–4 orders, lesser branches radial but from the margins of the slightly compressed main branches together with branchlets from their faces; lower branches 2–5 mm broad, 0.5–1 mm thick, ultimate branchlets terete, not or slightly basally constricted, 100–200 µm in diameter, with acute apices; hairs often numerous; some branches with terminal hooked, thicker, tendrils. Holdfast fibrous; epiphytic. Structure uniaxial, with a projecting apical cell and each axial cell with two periaxial cells; axial filament conspicuous in older branches, without rhizoidal filaments but with secondary pit-connections to inner cortical cells. Cortex 4–6 cells broad, inner cells ovoid and 20–40 µm in diameter, becoming 100–150 µm in diameter, surface rosettes usually present but weakly developed, cells 5–10 µm across. Rhodoplasts ovoid to elongate, becoming ribbon shaped and branched.

Reproduction. Sexual plants dioecious; procarpic. Carpogonial branches 3-celled, borne on mid cortical cells, orientated sideways with a reflexed trichogyne. Auxiliary cell next outwards from the supporting cell, becoming darkly staining as do adjacent cortical cells, with outer cortical cells dividing to form the pericarp and cells inward to the auxiliary cell cutting off small darkly staining nutritive cells. Following fertilization and fusion with the auxiliary cell, a gonimoblast initial is cut off laterally and divides to form gonimoblast filaments, some connecting with the nutritive tissue and others developing thallus outwardly to form branched, terminal chains of ovoid carposporangia 20–28 µm in diameter, together with some sterile filaments connecting to pericarp cells. Cystocarps on lesser branches, subspherical, protuberant and becoming basally constricted, 300–600 µm in diameter, with a pericarp 3–4 cells thick, non-ostiolate. Spermatangia covering the surface of branchlets, cut off via initials from outer cortical cells, ovoid, 1.5–2.5 µm in diameter. Tetrasporangia scattered in the cortex of young branches, often aggregated into sori part way along the branch and often on one side, pit-connected laterally to subsurface cells, ovoid, 20–35 µm in diameter, zonately divided.

Distribution.Safety Bay, W. Aust., to Walkerville, Vic., and the N coast of Tas.

Habitat. C. planicaulis is probably normally epiphytic on Amphibolis (both species) and larger algae.

[After Womersley, Mar. Benthic Fl. Southern Australia IIIA: 410–413 (1994)]