UC specimens and range limits for Saccharina sessilis

• 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: Attu Island, Aleutian Islands, Alaska (52.8, -173.15) to Santa Cruz, California (36.95089 -122.02618, UC1408296, 1948); disjunct to Point Sur, Monterey Co., Calif. (UC 96820, 1902); drift at San Simeon, San Luis Obispo Co..

Status: This species is easy to identify.

Habitat: Mid-intertidal zone.

Life History: Alternation of heteromorphic phases, with a macroscopic, annual sporophyte and dioecious microscopic gametophytes.

Search Sequences in GenBank

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

Hedophyllum Setchell 1901

Thallus a simple unbranched blade, without visible stipe and with haptera from lower blade margins. Sporangial thalli with holdfast of branched haptera. Stipe distinct at first, later disappearing in some specimens; blade short, broad and plane at first, often becoming bullate, not auriculate at base, later giving rise to branched haptera from lower margin. Haptera either scattered or whorled. Sori basal, irregular in outline.

Hedophyllum sessile (C. Ag.) Setch.

Laminaria sessilis C. Agardh 1824: 270. Hedophyllum sessile (C. Ag.) Setchell 1901: 121; Setchell & Gardner 1925: 617. L. apoda Harvey 1862: 167.

Stipe of young sporangial plant very short and much flattened, soon disappearing entirely; blade at first ovate and entire, soon splitting deeply, even to base, and becoming cucullate, in age becoming sessile, not greatly thickened at base, giving rise to haptera along sessile margin, 30-50(150) cm tall and 80 cm wide in quiet water, rarely more than 30 cm tall on exposed coasts; surface of blade either perfectly smooth or with irregular bullate swellings scattered over entire blade or only basal portion, with numerous mucilage ducts, these surrounded by small secretory cells; sori extensive, basal, irregular in outline.

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: Frequent in northern California.