Ulva taeniata (Setch.) Setch. & N.L.Gardner

Scientific Description

Habit and structure. Thallus light to medium green when living, drying darker, (10–)20–80(–175) cm long and 2–3(–5) cm broad, with a small discoid holdfast producing one to several elongate blades from shortly above the base; blades simple or occasionally branched, broadest near or somewhat above the base then tapering gradually to the tip, the sides moderately to strongly ruffled, often twisted usually with small, marginal few-celled spines. Cells in surface view arranged in short rows or irregularly, more or less isodiametric and (7–)10–15 µm across in central and upper parts of the thallus, becoming 20–25 µm across in the rhizoidal region near the base; pyrenoids 1–2 per cell, 2–3 in basal cells. Thallus in mid and upper parts 45–70 µm thick near the margins with cells L/B 1–2 and 20–25 µm long; 70–125 µm thick centrally with cells L/B (1–)2–2.5(–3) and 25–38 µm long; rhizoids confined to basal few mm of thallus which is then 110–160 µm thick, cells L/B (1–)1–2(–2.5) and 35–45 µm long, with a relatively thin central layer of rhizoids.

Reproduction. Gametes isogamous; not reported for Australian plants.

Distribution. Central California. New Zealand. In southern Australia, from Cottesloe, W. Aust., to Walkerville, Vic. and around Tasmania.

Habitat. Generally on rough-water rock platforms in the shallow subtidal.

[After Womersley, Mar. Benthic Fl. Southern Australia I: 149 (1984)]