Doubled Ribbon Weed

Ulva linza Linnaeus

Ulva linza Linnaeus, 1753:1163; Setchell and Gardner, 1920b:262, pl. 12: figs. 1–4; Levring, 1941:605; Smith, 1944:44, pl. 3: figs. 4, 5; Hayden et al., 2003:289, tbl. 4; Hayden and Waaland, 2004:378, tbl. 3; Mateo-Cid et al., 2006:48; Pacheco-Ruíz et al., 2008:191, 201.

Enteromorpha linza (Linnaeus) J. Agardh, 1883:134, pl. 4: figs. 110–112; Collins, 1909b:206; Howe, 1911:490; Doty, 1947:18, pl. 1: figs. 7–9; Dawson, 1961b:373; Dawson, 1966a:5; Norris, 1976a:76, fig. 32; Silva, 1979:340; Rocha-Ramírez and Siqueiros-Beltrones, 1991:30; Mendoza-González and Mateo-Cid, 1992:23; Mateo-Cid et al., 1993:51; Servière-Zaragoza et al., 1993:482; González-González et al., 1996:285, 371; Pacheco-Ruíz and Zertuche-González, 1996a:432; Yoshida, 1998:36, pl. 1-3: fig. G; Mendoza-González and Mateo-Cid, 1998:24; L. Aguilar-Rosas et al., 2000:133, 137; L. Aguilar-Rosas et al., 2002:235; Abbott and Huisman, 2004:50, fig. 7D; R. Aguilar-Rosas et al., 2005b:36.

Algae linear to lanceolate, unbranched blades, up to 40 cm long and up to 10 cm wide; composed of a flattened upper portion of 2 cell layers, with margins usually hollow and 1 cell thick; margins smooth or sometimes ruffled; and a lower portion that gradually tapers downward to a tubular, hollow monostromatic basal portion. Cells with a single cup-shaped chloroplast and usually 1 pyrenoid. Cells in surface view irregularly arranged in upper flat portions, 10–20 µm in diameter; cells in longitudinal rows in basal portions, elongated, up to 35 µm long. Cells in transection rectangular, up to 20 µm tall and to 35 µm wide.

HABITAT. On sand/mud covered rocks and shells in drainage channels of estuaries; occasionally in tide pools and shaded habitats; and epiphytic on crustose corallines (L. Aguilar-Rosas et al., 2000); mid to low intertidal.

DISTRIBUTION. Gulf of California: Las Piedras del Burro to La Paz. Pacific coast: Alaska to Baja California; Jalisco; Oaxaca; Chile; Juan Fernandez Island; Hawaiian Islands; Japan.

TYPE LOCALITY. “In Oceano” (Linnaeus, 1753:1163); Sheerness, Kent, England (Hayden et al., 2003:289).