UC specimens and range limits for Ulva lobata

• Blue markers: specimen records
• Yellow marker: type locality, if present
• Red markers: endpoints of range from literature

View map from the Consortium of Pacific Northwest Herbaria

Notes: Oregon to central California (Hayden & Waaland 2004).

Status: Most Ulva species are difficult to identify to species. Confirmed by sequence: British Columbia, Canada (Saunders & Kucera 2010); Yaquina Bay State Park, Oregon; San Simeon, San Luis Obisbo Co. (Hayden & Waaland 2004).

Habitat: Mid-low intertidal, subtidal

Life History: Alternation of isomorphic phases, with the sporophyte producing quadriflagellate zoospores and unisexual gametophytes producing biflagellate anisogametes; male and female gametes capable of parthenogenetic development (Tanner 1986; Chihara 1969a; Smith 1947).

Search Sequences in GenBank

Ulva Linnaeus 1753

Thalli membranous blades, broadly expanded, distromatic, mostly without hollow margins. Blades annual, mostly without stipe; rhizoidal processes from multinucleate lower cells extending downward between blade margins forming usually perennial holdfast. Cells of blade mostly uninucleate. Chloroplast single, laminate or cup-shaped, usually on outer face of cell, with 1 to several pyrenoids. Sporangial and gametangial thalli usually morphologically similar; fertile areas marginal or terminal; zoospores quadriflagellate. Gametes biflagellate, isogamous or anisogamous. Zygote germinating without dormant period.

"Gomontia polyrhiza," which may be a stage in the life history of species of Ulva, is described on p. 120.

Ulva lobata (Kütz.) S. & G.

Phycoseris lobata Kützing 1849: 477. Ulva lobata (Kütz.) Setchell & Gardner 1920a: 284; 1920b: 268; Smith 1944: 46.

Blades rich grass-green, broadly obovate, often deeply lobed or divided, slightly to deeply ruffled, with smooth or undulate margins, 10-30 cm tall, to 15 cm broad, 40-50 µm thick at margins to 90 µm in middle, the blade base gradually narrowed and sometimes stipelike; cells irregularly arranged, in anticlinal section 10-12 µm diam., 28-30 µm long, the chloroplast filling outer third of cell, usually with 1 pyrenoid; gametes anisogamous.

On rocks or occasionally epiphytic, midtidal to subtidal, Ore. to Guerrero, Mexico, and to Ecuador and Chile (type locality); common intertidally in C. Calif.

Excerpt from Abbott, I. A., & Hollenberg, G. J. (1976). Marine algae of California. Stanford University Press, Stanford, California. xii [xiii] + 827 pp., 701 figs.

Notes: Morphology ranges from short, tufted, deeply divided blades in the upper intertidal to large, lobed blades in the low intertidal, with smaller, higher plants in the southern part of its range. The geographical range is smaller than previously thought.