Under the hand lens
Photo: Caloplaca limonia is a newly described species from the Caloplaca citrina group and recently accepted by the BLS as a British species. Lichens.ie (Paul Whelan) has now recorded it in Ireland. Distinguished from Caloplaca citrina by its pale milky colour (due to the large blastidia) and the wide apothecial rim (also covered in blastidia) and bright orange discs – (Description summarised from Powell & Vondrák (2012) and BLS Bulletin 110: 64 (2012)). read more
Leptogium cochleatum is a rare Irish lichen [profile] found on the bark of mature hazel and ash trees. Since the year 2000 it has only been recorded at one site in Co. Galway, two sites in Co. Clare and one site in Co. Kerry. Its decline is due directly to habitat destruction and the non-replacement of mature trees. Lichens need habitat continuity due principally to their slow metabolism and lengthy life cycle. This vulnerable beautiful wavy gelatinous foliose lichen empasises the need for an Irish Lichen Red Data book. [click photo].
New to lichen identification? Then this image will interest you. It’s a close up of an apothecium, a lichen’s sexual reproductive structure. The apothecia are an important aid to lichen identification. Most have a rim; sometimes the rim is the same colour as the thallus, sometimes not; the area inside the rim is the disc; this can be flat, convex or concave, it may have crystals on it or not, and so on. Combined with other anatomical lichen parts it can lead to a secure identification. Read more here…..
Lead and other metals, particularly iron and copper, are toxic to many lichens. Some lichens will grow on stone bathed by lead contaminated water, but almost never directly on lead itself. The photograph here shows two lichen species doing their utmost not to grow on the lead lettering on this gravestone. Caloplaca flavescens (orange) normally grows in a circular manner, but here is working its way between the 9 and 0 to take on the symbolic shape of a hour-glass. Click on the photograph to enlarge.
Cladonia botrytes has never been found in Ireland. It’s likely it is here. However, its small size (about 5 mm high), its growth among other Cladonia species and its specific requirements have probably all contributed to its elusiveness. All Scottish specimens have been found on coniferous tree trunks exposed to direct sunlight for a short time of the day. Critically the exposed cut wood has not been chemically treated. You can report a sighting to info [at] lichens.ie (replace [at] with @).