Lichen: Cetraria islandica
Name: Cetraria islandica (L.) Ach.(1830)
Pronunciation: cetraria islandica
Conservation Evaluation: Least Concern
Body Type: Foliose /Fruticose
Description: A chestnut brown resin-like shrubby thallus ranging in height from 2-6cm. The lobes are long and narrow and deeply channelled with many small projections along the margins. They tend to curl back in towards the body of the thallus. The base is frequently reddish brown and pitted. Overall it gives the appearance of a tangled mass loosely attached to the substrate. The marginal projections vary in size from 0.1 to 1mm. Dark pycnidia occupy the tips of the projections. White pseudocyphellae populate the lower surface right to the margins of the lobes. Apothecia are very rare; discs vary from 2-20mm in diameter and the rims are distinct and crenulate.
Chemical Tests: C-, K-, KC-, Pd+ orange, UV-
Nature Notes: Found in upland regions, especially among mosses and heather. Rare in Ireland, but locally abundant where it occurs. It is known as Reindeer Moss and is eaten by Reindeer and Caribou.
Photographed: in Co. Mayo just north of Clew Bay.
Vice county distribution map: See Map
Link: Map this species on the Lichen Survey
Other species recorded in Ireland:
Cetraria aculeata (Schreb.) Fr.
Cetraria ericetorum Opiz
Cetraria islandica (L.) Ach.
Cetraria muricata (Ach.) Eckfeldt
Cetrelia olivetorum (Nyl.) W.L.Culb. & C.F.Culb.
Text and images © Paul Whelan, 2010.