UC specimens and range limits for Coilodesme rigida

• 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: In California, from Latigo Shore Drive, Los Angeles Co. to San Diego Co.; Santa Catalina, San Clemente and San Nicolas islands.

Status: This genus needs to be studied with molecular methods to confirm species boundaries.

Habitat: Low intertidal to shallow subtidal in exposed and moderately sheltered environments.

Life History: Probably alternation of heteromorphic phases, with zoospores from unilocular sporangia on macroscopic sporophytes germinating to produce tufts of diffusely branched filaments bearing plurilocular organs, subcultures of which produced successive generations of presumed plethysmothalli bearing both unilocular and plurilocular organs; macroscopic sporophytes not obtained in culture (Wynne 1972a).

Search Sequences in GenBank

Coilodesme Stromfelt 1886

Thalli saccate, cylindrical to flattened, entire or sometimes with frayed divisions at maturity, mostly epiphytic, usually briefly stipitate, attached by a small disk or with rhizoids apparently penetrating host. Cortical cells mostly not in anticlinical rows, progressively larger inward. Chloroplasts discoid, without pyrenoid. Unangia narrowly to broadly pyriform or very irregular in form, scattered and singly embedded just below surface. Gametangial plants microscopic, bearing uniseriate plurangia.

Coilodesme rigida S. & G.

Setchell & Gardner 1924b: 9; 1925: 584.

Thalli firm and leathery, dark brown to medium brown, strictly complanate, the surface and margins smooth, the apex broadly rounded, the stipe short and thick, the blades 5-10(25) cm long, 1-2.5 cm broad, 300-375 µm thick, with thicker margins; outer cortex of anticlinal cell rows, the inner cortex with slender filaments extending in all directions among larger cortical cells; sporangia irregular in shape, several times longer anticlinally than diam.

Frequent on Halidrys dioica, upper subtidal to lower intertidal, Redondo Beach (type locality), Calif., to Bahia Tortuga, Baja Calif.; common on Santa Catalina I., 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.