Perischelia glomulifera (J.Agardh) Kylin

Scientific Description

Habit and structure. Thallus medium to dark red-brown, 5–20(–30) cm high, much branched irregularly with extended axes or long branches, heavily corticated, upper branches bearing short glomeruliferous tufts 1–2 mm long and across, on a short corticated stalk bearing branched monosiphonous filaments 1–2 mm long. Holdfast discoid, 2–5 mm across; epilithic. Structure. Axial cells enlarging rapidly from apices, becoming 200–800 µm in diameter and L/D (1.5–)2–4 in mature branches, thick walled, corticated from close to apices by compact rhizoidal filaments of inner elongate cells, surface cells short, isodiametric, 2–3 µm across, forming a smooth, compact, surface layer. Axial cells clearly visible along the branches in dried specimens, with the end walls supporting the cortex slightly more than the side walls. Glomeruliferous tufts on short, corticated, lateral branches, bearing several to many determinate, more or less alternately pinnate, branchlets 0.5–1 mm long, with slender basal cells 25–35 µm in diameter and L/D 1.5–3, mid rachis cells 40–85 µm in diameter and L/D 1–1.2, tapering only slightly in the pinnules to 30–50 µm in diameter and L/D 0.8–1.2 until the 1–3 terminal cells, with a small mucronate end cell. Rhodoplasts discoid.

Reproduction. Unknown. Short-stalked globular bodies 300–650 µm in diameter occur on the glomuliferous laterals on most thalli, composed of a central mass of short-celled filaments bearing compact radiating filaments with terminal, narrowly clavate, cells 3–5 µm in diameter and L/D 4–6. Function unknown.

Distribution. Champion Bay, W. Aust., to Port Phillip Heads, Vic.

[After Womersley, Mar. Benthic Fl. Southern Australia IIIC: 419–422 (1998)]