From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

Dead man's fingers (Codium fragile) off the Massachusetts coast
Scientific classification edit
(unranked): Viridiplantae
Division: Chlorophyta
Class: Ulvophyceae
Order: Bryopsidales
Family: Codiaceae
Genus: Codium
Stackhouse, 1797
Type species
Codium tomentosum

See text

Codium cylindricum Holmes, type definition herbarium specimen.

Codium is a genus of seaweed in the Chlorophyta of the order Bryopsidales. There are about 50 species worldwide.[1]


The genus has thalli of two forms, either erect or prostrate. The erect plants are dichotomously branched to 40 centimetres (16 in) long with branches forming a compact spongy structure, not calcareous. The final branches form a surface layer of close palisade cortex of utricles. The non-erect species form either a prostrate or globular thallus with a velvet-like surface, the final branches forming a close cortex of utricles.[2]



Two of these species are very rare in Ireland. Codium adhaerens has been recorded from a few sites on the west coast and from Tory Island on the north coast in County Donegal. In 1837 it was found in Church Bay in County Antrim,[3] but has not been found there since.

There are other species of "doubtful validity":- Codium amphibium is included in William Henry Harvey's Phycologia Britannica Pl.xxxv. and noted as: "spreading in patches of great extent along the edge of the sea, over the surface of a turf-bog which meets the shore at Roundstone Bay" (Ireland).



  1. ^ C. van den Hoek; D. G. Mann; M. H. Jahns (1995). Algae: An Introduction to Phycology. Cambridge: Cambridge University Press. ISBN 978-0-521-30419-1.
  2. ^ E. M. Burrows (1991). Seaweeds of the British Isles. Volume 2. Chlorophyta. London: Natural History Museum. ISBN 978-0-565-00981-6.
  3. ^ Morton,O. 1994. Marine Algae of Northern Ireland. Ulster Museum. ISBN 0 900761 28 8
  4. ^ Abbott, Isabella A (1989). Lembi, Carole A.; Waaland, J. Robert, eds. Algae and human affairs. Cambridge University Press, Phycological Society of America. p. 141. ISBN 978-0-521-32115-0. Food and food products from seaweeds

General references[edit]

External links[edit]