Ulva fasciata Delile
Descr.Egypte,Hist.Nat. 297-298 [153-154], pl. 58 fig. 5 (1813)

Conservation Code: Not threatened
Naturalised Status: Native to Western Australia
Name Status: Current


IMCRA Regions: Central West Coast, Leeuwin-Naturaliste.

Local Government Areas (LGAs): Fremantle, Rockingham.

Scientific Description
John Huisman & Cheryl Parker, Thursday 8 September 2016

Habit and structure. Thallus grass-green to brownish-green on drying, 20–45 cm high, with a small discoid holdfast, divided shortly above the base into numerous, simple or branched, relatively flat and smooth, elongate-lanceolate branches, each slightly to distinctly constricted basally, broadest (1–2(–4) cm) a few cm above the base and then tapering fairly evenly to a slender tip 1–4 mm broad; margin relatively smooth to slightly irregular or with occasional coarse spinous projections; surface even, in some branches with a lighter-coloured, broad central region in dried specimens. Cells in surface view arranged in slight, often curved rows or irregularly, isodiametric to elongate and (8–)10–13(–15) µm across in central and upper parts of branches, (10–)12–17 µm across in lower rhizoidal parts where rhizoid-producing cells are rounded and 16–25 µm across; pyrenoids (1–)2–3 per cell. Thallus (70–)90–115(–140) µm thick in mid and upper parts with cells L/B about 2 and (25–)30–45(–50) µm long; 100–140 µm thick in lower parts with cells L/B 1–2 and 30–45(–50) µm long; and 150–250 µm thick with cells L/B 3–4 and 35–50 µm long where rhizoids develop and become densely aggregated as a central mass up to 100 µm thick.

Reproduction. Gametes isogamous, also developing parthenogenetically.

Distribution. Widely distributed in warmer seas though probably some references to this species are doubtful.

Habitat. Epilithic in the lower eulittoral and shallow sublittoral.

[After Womersley, Mar. Benthic Fl. Southern Australia I: 146 (1984)]