UC specimens and range limits for Ralfsia pacifica

• 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: Crusts are underrepresented in herbaria; collections in UC are from Sonoma and Marin counties, Los Angeles Co.; Santa Barbara and Santa Catalina islands; and San Diego. Other herbaria hold specimens from Vancouver Island, British Columbia, Canada, Washington and Oregon, as well as Hawaii, the Gulf of California, Mexico and mainland Mexico. Identities should be checked.

Status: This species has not been investigated in California; the genus needs evaluation.

Habitat: On rock in upper to midtidal zones and in pools

Life History: Plurilocular and unilocular organs have been found on separate crusts. Cultures from one isolate from central California was initiated from zooids from plurilocular organs. These grew into crusts, but were not followed beyond that stage (Wynne 1972).

Search Sequences in GenBank

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

Thalli crustose, often confluent, olive brown to dark brown, irregularly circular, (2)5-20 cm diam., 0.4-1 mm thick, firmly attached to substratum without rhizoids, frequently with prominent radial and concentric ridges; cells of basal stratum 10-16 µm diam., 1.5-2.5 times as long, merging assurgently into similar forking cell rows, these narrowing gradually to erect filaments; upper cells of erect filaments 7-10 µm diam., mostly 0.7-1.5 times as long; chloroplast single; hair pits frequent; sori small, 1 mm diam. or less; unangia oblong to subclavate, 70-90 (140) µm long, 18-30 µm diam., sessile at base of paraphyses; paraphyses 90-120 (180) µm long, of 7-12 cells, these 6-9 µm diam., 1-1.5 times as long near apex, 2-2.5 times as long toward much narrower base; plurangia 40-90 µm long, 5-6 µm diam., uniseriate, terminal on erect filaments, with single sterile terminal cell +/- 1.5 times as long as diam.

Common on rocks, midtidal to upper intertidal, Alaska to Sinaloa, Mexico. Type locality: Corona del Mar (Orange Co.), 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.