Ulva lactuca L.
Sp.Pl. 1163 (1753)

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

Distribution

Beard’s Provinces: Eremaean Province, South-West Province.

IBRA Regions: Avon Wheatbelt, Carnarvon, Jarrah Forest, Swan Coastal Plain.

IBRA Subregions: Avon Wheatbelt P1, Cape Range, Perth, Southern Jarrah Forest.

IMCRA Regions: Abrolhos Islands, Canning, Central West Coast, Leeuwin-Naturaliste, Otway, Pilbara (offshore), Shark Bay.

Local Government Areas (LGAs): Albany, Ashburton, Broome, Bruce Rock, Cockburn, Cottesloe, Fremantle, Greater Geraldton, Irwin, Joondalup, Karratha, Mosman Park, Nedlands, Peppermint Grove, Perth, Port Hedland, Rockingham, Shark Bay, South Perth, Subiaco, Wanneroo.

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

Habit and structure. Thallus grass-green, usually with a single frond from the holdfast, entire or irregularly lobed or divided, to 15 cm long and 1–10 cm across; margin entire, surface smooth. Cells in surface view in short rows becoming more irregular below, isodiametric to slightly elongate, (10–)12–18(–20) µm across or long above, 20–25 µm long below; pyrenoids 1–2(–3) per cell. Thallus 40–60 µm thick in upper parts with cells in sectional view rather square to rectangular, L/B 1.0–1.4 and 18–22 µm long; 60–85 µm thick in mid and lower parts with cells in section L/B 1–1.2(–1.4) and 22–26 µm long, becoming 75–100(–250) µm thick near the base with a narrow to moderately broad central mass of rhizoids.

Reproduction. Generations isomorphic, the sporophyte producing quadriflagellate zoo(meio)spores, and the gametophytes unisexual with biflagellate anisogametes which can germinate directly to form the gametophyte again.

Distribution. Recorded from several locations in W. Aust. In southern Australia, known from Christies Beach and St Kilda, S. Aust. and Port Phillip, Vic.

[After Womersley, Mar. Benthic Fl. Southern Australia I: 141 (1984)]