Sphacelaria novae-hollandiae Sond.

Scientific Description

Habit and structure. Thallus medium to dark brown, 5–10(–15) mm long, densely tufted, usually epilithic with a stoloniferous, compact, base. Branching of erect filaments frequent with numerous short to long laterals at narrow to moderate angles, slenderer than main filaments and some of limited growth; phaeophycean hairs frequent, 7–10 µm in diameter. Filaments in upper parts 40–50(–60) µm in diameter, becoming (48–)50–70 µm in diameter below, with segments L/B0.5–1.0 and showing 3–5 longitudinal walls; secondary transverse walls absent.

Reproduction. Propagula (100–)150–200 µm long and 80–120 µm across the arms, borne on a 1–3 celled uniseriate pedicel, with the two arms tapering to a rounded terminal cell cut off by either a straight or angled cross wall, and with a small lenticular cell midway between the arms. Unilocular sporangia ovoid to subspherical, pedicellate, borne in small clusters, 24–36 µm in diameter. Plurilocular sporangia borne in small clusters on lower branches, pedicellate, 35–45 µm long and 25–40 µm in diameter.

Distribution.From Rottnest I., W. Aust., around southern Australia to Port Stanvac, S. Aust.

Habitat. Usually in the lower eulittoral.

[After Womersley, Mar. Benthic Fl. Southern Australia II: 158 (1987)]