Griffithsia teges Harv.

Scientific Description

Habit and structure. Thallus dark red, coarse, 2.5–17(–20) cm high; eulittoral plants stiff and sometimes erect, forming extensive mats with filaments more or less adpressed, deeper plants more openly branched, irregularly subdichotomous. Attachment by a wad of twisted and anastomosing rhizoids from cells near the thallus base; epilithic. Structure. Filaments gradually attenuate towards obtuse apices, slightly constricted at the nodes, loosely clothed with rhizoids below. Cells cylindrical to doliform, 0.4–0.8 mm in diameter and L/D 2–4.

Reproduction. Gametophytes dioecious. Female axis 3-celled, flanked by 2 pairs of minute hair-like synchronic laterals, subapical but displaced laterally by continued growth of the apical cell. Procarp systems subapical, each with a sterile lateral cell and supporting cell bearing 1(–2) sterile cells apically and 1(–2) lateral, recurved carpogonial branches of 4 cells; hypogenous cell producing abaxially 6–10 two-celled involucral branches; the sub hypogenous cell swollen towards its upper end. Post-fertilization fusion cell columnar, bearing 1–3 gonimolobes terminally, most cells of which become ovoid (-clavate) carposporangia, 40–65 µm in diameter. Spermatangia borne on numerous, minute fascicles clustered in the constrictions between swollen, obovoid and globose cells 750–1250 µm in diameter at the base of a short lateral branch 3–6 cells in length, similar in appearance to those associated with tetrasporangial clusters; filaments including globose cells above fascicles often caducous, so that mature fascicles appear terminal on the basal ovoid cells which become 880–1500 µm in diameter; fascicles initially polychotomous, later laterally branched; involucral cells absent. Tetrasporangia borne on numerous minute fascicles in the constrictions between ovoid and globose cells at the base of short laterals with the upper cells often caducous; involucre absent. Fascicles producing clusters of 2–6 lachrimiform tetrasporangia 46–88 µm in diameter.

Distribution.Fremantle, W. Aust., to Wilsons Promontory, Vic. and Bass Strait.

Habitat. G. teges is a ubiquitous and common species growing in coarse mat-like strata from the lower eulittoral-upper sublittoral, on jetty piles and rock, and to a depth of 21 m, generally on rough-water coasts.

[After Womersley, Mar. Benthic Fl. Southern Australia IIIC: 322–324 (1998)]