UC specimens and range limits for Leathesia marina

• 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: Cosmopolitan. On the west coast, from Attu Island, Aleutian Islands, Alaska through Mexico.

Status: This species has been analyzed using DNA sequences in the context of the systematic position of Petrospongium (Cho & Boo 2006, Racault et al. 2009); it is clearly within the Chordariaceae.

Habitat: Growing on turf algae or rock on intertidal reef flats, or epiphytic on Neorhodomela larix and Odonthalia floccosa in the mid intertidal

Life History: Plants from Sweden and France bore unilocular organs exclusively when they were small (young), and plurilocular organs exclusively when they were large (old). Isolates started with zooids from plurilocular organs grew into branched filamentous creeping systems. No mating was observed. The creeping systems took two paths: 1) they formed assimilatory filaments and thus small cushions with plurilocular organs, thought to represent small Leathesias, 2) they formed uniseriate plurilocular organs directly on the creeping system. Sauvageau (1925) equated the creeping system with Myrionema, and took it through 6 generations of plurilocular plants (Kylin 1933; Sauvageau 1925).

Search Sequences in GenBank

Leathesia S. F. Gray 1821

Thalli of sporangial plants globular and fleshy, mucilaginous; inner tissue of large, colorless cells in radiately branched filaments; cortical layer of pigmented smaller cells forming palisade-like filaments 3-6 cells long, usually with enlarged terminal cell and with or without fascicles of long, colorless hairs projecting beyond surface. Unangia and plurangia arising at base of cortical filaments. Gametangial plants microscopic, filamentous, with plurangia.

Leathesia difformis (L.) Aresch.

Tremella difformis Linnaeus 1755: 429. Leathesia difformis (L.) Areschoug 1847: 376; Smith 1944: 114 (incl. synonymy).

Thalli yellowish-brown, globular to irregularly expanded, to 12 cm diam., hollow and much convoluted at maturity, surface texture slippery, commonly with numerous hair fascicles; unangia ovoid, 40-50 µm long, 18-24 µm diam.; plurangia uniseriate, 30-45 µm long, 4-6 µm diam., of 7-10 short cells, usually in clusters among cortical filaments.

Annual, common early spring to October, on rocks or occasionally epiphytic, very abundant in sheltered locations, midtidal to upper intertidal, Bering Sea to Baja Calif. and Chile; common throughout Calif. Also Europe. Type locality: Sweden.

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: Scagel et al. (1993) placed L. nana Setchell & Gardner in the synonymy of this species, which is now known as Leathesia marina.