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Name derivation:

Phycodrys= Gr. phycos: algae + drys: an oak tree

fimbriata= L. fimbriatus: bordered with a fringe or fringed

Common names: sea oak, oak leaf, or oak leaf weed


Phycodrys Kützing, 1843;  25 of 44 species descriptions are currently accepted taxonomically (Guiry and Guiry 2014).



Algae are erect, 10-15 (-20) cm tall, foliaceous with lanceolate to ovate blades with midribs and lateral veins, and attached by a fibrous base.  Older fronds are deeply lobed, bright purple-red, 2-5 (-12) cm wide, and may extend along the stipe to the holdfast.   Midribs obvious;  axial cell surrounded by pseudoparenchymatous cells, and with oblique, lateral faint veins.  Margins serrate or wavy and lateral lobes may form large blades. Tetrasporangia tetrahedral, in sori at ends of veinlets, near margins of main blades, or on small lateral leaflets.  Spermatangia in yellowish narrow sori along blade margins.  Cystocarps irregularly scattered on primary blades or lateral leaflets of older algae. Fronds perennial or pseudoperennial.

Similar genera:

Hommersand and Lin (2009), using rbcL sequences, noted that Phycodrys rubens in North American is probably P. fimbriata .


Common but previously confused with Phycodrys rubens. algae are perennial, epiphytic on other algae, on stone or shells within low tide pools, and within the sublittoral zone to 40 m.




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.

Hommersand, M. S. and S.-M. Lin. 2009. Phylogeny and systematics of species of Phycodrys and Membranoptera (Delesseriaceae, Rhodophyta) that exhibit trans-Arctic distributions between the North Pacific and North Atlantic Oceans. In: Abstracts , 48th Northeast Algal Symposium, Univ. Massachusetts, Amherst, p. 23.

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