UC specimens and range limits for Pleurophycus gardneri

• 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: This species is common in Alaska, British Columbia, Canada, and northern Washington, but less frequent in the intertidal zone in Oregon and California. Most California specimens are from Mendocino, Sonoma and Monterey counties, but it may be far more common, especially at depth. VanBlaricom et al. (1986) reported it from Point Piedro Blancas, San Luis Obispo Co., from depths up to 27m. Spalding et al. (2003) confirmed its deep water distribution in Monterey Co. (30-45m).

Status: This species is easy to identify. Studies of deep water communities off central California from Cypress Point to Point Sur, Monterey Co. (Spalding et al. 2003) revealed a community at 30-35m where Pleurophycus dominates, attaining densities of 10 plants per square meter.

Habitat: Lowest intertidal in the north, subtidal to 35m in central California.

Life History: Alternation of heteromorphic phases (large diploid sporophyte and microscopic haploid dioecious gametophytes). Perennial, but blade is renewed from the growth zone at the base of the blade (intercalary meristem) (VanBlaricom et al. 1986). Sori (patches of sporangia containing spores) occur on the midrib as dark patches.

Associated Taxa: At 30-35m, Pterygophora californica, Eisenia arborea, Nereocystis luetkeana, Desmarestia tabacoides

Search Sequences in GenBank

Illustration from DeCew's Guide to the Seaweeds of British Columbia, Washington, Oregon, and Northern California

Pleurophycus Setchell & Saunders 1900

Holdfast of sporangial plant branched. Stipe simple. Blade undivided, with single broad longitudinal midrib; lateral portions of blade broad and ruffled. Mucilage ducts absent throughout plant; sori produced on either side of midrib.

Pleurophycus gardneri Setch. & Saund.

Setchell & Saunders 1900: no. 346; Setchell & Gardner 1925: 606; Kjeldsen 1972: 416.

Sporangial thalli probably annual; holdfast of numerous whorls of rigid haptera, usually 10 cm or less broad; stipe 39-50 cm long, solid, terete at base, gradually flattening toward base of blade; blade flabby, elastic, delicately wrinkled near midrib, the margin entire in healthy plants, the blade 60-90 cm long, to 40 cm broad, dark olive green in life. Frequent in northern part of range, saxicolous, low intertidal to upper subtidal, Montague I., Alaska, to Coos Bay, Ore.; rare in Calif., from Ft. Bragg and Salt Pt. (Sonoma Co.). Type locality (lectotype): Whidbey I., Wash.

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: Sori (patches of sporangia containing spores) occur on the midrib as dark patches. Juvenile sporophytes have thin blades with wedge-shaped bases; the midrib begins to develop as a dark area near the top of the stipe. It develops toward the tip of the blade as a darker stripe.