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Name derivation:



Polyides  C.Agardh  1822;  1 of 8 species descriptions is currently accepted taxonomically (Guiry and Guiry 2014).

Order Gigartinales;  Family Polyidaceae



Algae bushy, usually forming dense tufts;  dull red, drying to black, firm, elastic, horny when dry, and attached to a large discoid holdfast.  Axes almost terete, abruptly tapering to slightly acute or blunt tips, with narrow forks and branching limited below. Tetrasporangia cruciate, in sori  that cause swollen branch tips. Gametophytes dioecious; spermatangia covering surfaces of short filaments in upper branch forkings. Cystocarpsic and spermatangial nemathecia either oval or cylindrical and forming wart-like swellings on the branches. algae are perennial.

Similar genera:

The alga looks superficially like Furcellaria lumbricalis, but it has a discoid rather than a fibrous holdfast  and abrupt versus gradually tapered tips. Polyides is also similar to Ahnfeltia, except that it is not as stiff and broader than Ahnfeltia.

Medical application:

An anti-coagulant (Pal 2013)


Uncommon to locally abundant, growing on outcrops or large boulders. A psammophytic species like Ahnfeltia plicata, tolerating protracted sand burial and abrasion. Forming extensive turf-like beds or free floating in low littoral pools; extending to 20m within the sublittoral zone

From Arctic Europe to northern Spain and Baltic Sea in Europe. From Arctic Canada to New York in western Atlantic. Located up to 12m deep from intertidal zone (Guiry and Guiry 2014).




Guiry, M.D. and G.M. Guiry  2014.  AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 2 May 2014.

Pal, D., T. De and A. Baral. 2013. Marine Natural Products with Special Reference to Aplidine as a New Bioactive Compound in Anti-cancer class. International Journal of Pharmaceutical and Chemical Sciences 2:1067-1075.

Taylor, W. R.  1957. Marine Algae of the Northeastern Coast of North America. Revised edition. Univ. Michigan Press., Ann Arbor, ix + 509 pp. (as Polyides caprinus)