Ahnfeltia fastigiata
(Endlicher) MakienkoKey Characteristics
- Clumps of dark, narrow, wiry branches arising from tangled stolons
- Branching dichotomous, with forked tips, sometimes lighter than lower parts
- Growing on rock, often partially buried in sand
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- Yellow marker: type locality, if present
- Red markers: endpoints of range from literature
Status: Reported as [Ahnfeltia plicata] (Hudson) Fries, type locality England, but now known as [Ahnfeltia fastigiata] (Endlicher) Makienko, type locality Sitka, Alaska. Ahnfeltia, as defined by A. plicata (Hudson) Fries, the type species, has compound external carposporophytes whose development was elucidated by Maggs & Pueschel (1989). This unique pattern of reproduction together with certain other characters justified the establishment of the family Ahnfeltiaceae and the order Ahnfeltiales (Maggs & Pueschel 1989). DNA sequences from Bodega Head, Sonoma Co.
Habitat: Mid-low intertidal, usually associated with sand
Illustration from DeCew's Guide to the Seaweeds of British Columbia, Washington, Oregon, and Northern California
Illustration from DeCew's Guide to the Seaweeds of British Columbia, Washington, Oregon, and Northern California
Ahnfeltia Fries 1835
Thalli erect, with numerous cylindrical to slightly compressed branches arising from cylindrical rhizomes. Branches repeatedly dichotomous or irregularly branched, rigid to wiry. Medulla partly of narrow, parallel, longitudinal filaments. Outer cortex of radially arranged, firmly adjoined cell rows. Monosporangia produced in nemathecioid enlargements of branches, these the only known reproductive structures.
Ahnfeltia plicata (Huds.) Fries
Fucus plicatus Hudson 1762: 470. Ahnfeltia plicata (Huds.) Fries 1835: 310; Smith 1944: 271.
Thalli purplish-black, 5-14 cm tall; branches numerous, cylindrical, wiry, densely irregularly branched, the branches 250-500 µm diam., with proliferous branches arising mostly on mature lower parts; reproduction not observed in Calif. specimens.
Common in restricted localities, usually half-buried in sand, midtidal to lower intertidal, Bering Sea to Baja Calif. Widely distributed. Type locality: England.
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: The re-identification of Ahnfeltia plicata from California as A. fastigiata was the work of Makienko (1970), confirmed by Maggs, McLachlan, & Saunders (1989). The type locality of Gigartina fastigiata P. & R. is Sitka. Harvey (1853: 168) considered it a variety of A. plicata . Makienko's conclusion seems reasonable from a biogeographic point of view. He interprets A. plicata as a high-latitude circumboreal species. Because Gigartina fastigiata P. & R. is illegitimate, it cannot serve as a basionym. Chondrus fastigiatus Endlicher, although intended to be a new combination, is treated as a new name and the accepted basionym. Maggs & Pueschel (1989) removed Ahnfeltia from the Phyllophoraceae and established the family Ahnfeltiaceae to accommodate it. Simultaneously they established the order Ahnfeltiales to accommodate the new family.
NATIVE
Vertical Distribution: Mid-low intertidal
Type locality: USA: Alaska: Sitka