UC specimens and range limits for Fredericqia decewii

• 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

Life History: Alternation of heteromorphic phases between a macroscopic perennial gametophyte and a crustose "Petrocelis" tetrasporophyte was observed in culture using plants from from Horseshoe Cove, Sonoma County, California (DeCew 1983). Gametophytes were erect and presumably dioecious. Following fertilization, cystocarps developed within the female blades; carpospores were released and grew into Erythrodermis-like crusts which possibly formed sporangia when planted out in the field (surface pits and sporelings were observed).

Search Sequences in GenBank

Ahnfeltia gigartinoides J. Ag.

J. Agardh 1847: 12; Smith 1944: 272.

Thalli tufted, deep red to purplish-black, 10-30 cm tall, 10-15 times dichotomous, somewhat distichous; branches rigid, cylindrical to subcylindrical, 0.5-1 mm diam; sometimes with short, simple, proliferous branches on basal parts. Reproduction imperfectly known.

Frequent to uncommon on intertidal or subtidal rocks, Vancouver I., Br. Columbia, to Pta. Santo Tomas, Baja Calif. and southward. Type locality: St. Augustine (Oaxaca), Mexico.

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: DeCew (1983) showed that this species, first identified by Farlow (1875) as Ahnfeltia gigartinoides J. Agardh, was not conspecific with specimens of A. gigartinoides from near the type locality in tropical Mexico. The Californian gametophytes differed from the Mexican in their habitat (low intertidal sand-covered rocks vs. high intertidal pools), habit (100- 200 mm high, with narrow axes vs. 30-40 mm high stout axes), and position of cystocarps (on main axes or lateral proliferations vs. terminal). DeCew concluded that the Californian species represented was undescribed, and called it Ahnfeltiopsis pacifica DeCew & P.C. Silva ex P.C. Silva (1979), but its publication was invalid because it lacked a Latin diagnosis and no type specimen was indicated. Ahnfeltia gigartinoides from Mexico was later transferred to Ahnfeltiopsis by Silva & DeCew (1992).