Lichen: Ramalina siliquosa
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Name: Ramalina siliquosa (Huds.) A.L.Sm.
Ramalina siliqosa photographed on Skellig Michael, 2009.
Pronunciation: Ramalina siliquosa
Popular Name: Sea Ivory Body Type: Fruticose
Conservation Evaluation: Least Concern
Description: The thallus is erect (typically 3 cm to 5 cm in height), brittle, pale green-grey and sometimes rises from a crustose base. Apothecia are common, appearing more frequently on the sides of the thalli branches rather than the ends. The branches are strap-like and 2 mm to 9 mm wide with little ridges and distinct white spots towards the tips. Spores are ellipsoidal or kidney shaped. Apothecia are lecanorine. Pycnidia are frequent. The yellow tint in this group is due to the presence of usnic acid. This acid protects the green algae from UV light.
Chemical Tests: Complex leading to ‘chemical races’.
Nature Notes: Ramalina siliquosa grows on rocks with a high silica content and is considered a maritime species, being found typically on the upper part of rocky sea shores (Supralittoral – Xeric), especially in Ireland. However, specimens have been found inland 40 km from the sea. It seems to have a dependency on salt spray (which possibly neutralises the highly siliceous [acid] rocks that it grows on). Specimens far from the sea may survive by living on rocks with low silica content which receive an infrequent dose of sea salt.
Most species in the Ramalina group are sensitive to air pollution ( as are the groups Bryoria and Usnea). R. siliquosa is often the dominant species and when abundant enough is eaten by sheep and goats.
Vice County distribution map of Acarospora fuscata: See Map
Link: Map this species on the Lichen Survey
Other species recorded in Ireland
- Ramalina calicaris (L.) Fr.
- Ramalina canariensis J.Steiner
- Ramalina chondrina J.Steiner
- Ramalina cuspidata (Ach.) Nyl.
- Ramalina farinacea (L.) Ach.
- Ramalina fastigiata (Pers.) Ach.
- Ramalina fraxinea (L.) Ach.
- Ramalina lacera (With.) J.R.Laundon
- Ramalina polymorpha (Lilj.) Ach.
- Ramalina portuensis Samp.
- Ramalina subfarinacea (Nyl. ex Cromb.) Nyl.
Text and images © Paul Whelan, 2009.