Lichen: Usnea subfloridana

Usnea subfloridana: section through the main stem showing the medulla and cortex.Note green photobiont layer.
Name: Usnea subfloridana Stirt.
Pronunciation: Usnea subfloridana
Popular Name: Old man’s beard. Body Type: Fruticose
Conservation Evaluation: Least Concern
General Description: Bushy, pendulous lichen with colours in the grey-green to yellow-green range, with a distinctive blackened base with annular rings or cracks. The branches are cylindrical and tapered (no flattening). The side branches are not narrowed where they attach to the trunk (they are in some species). The trunk and branches are covered in patches of soredia or isidia. Apothecia are rare and when present there are very few (maybe three on a specimen). Some specimens may consist of just a single stem and a few side branches. This divergent range of types (bushy to simple stems) makes Usnea difficult to identify.
Chemical Tests: K + yellow instantly, Pd + medulla turns yellow-orange.
Nature Notes: This is the most common Usnea in Ireland and also the most resistant to air pollution.
Vice County distribution map of Acarospora fuscata: See Map
Link: Map this species on the Lichen Survey
Other species recorded in Ireland
- Usnea articulata (L.) Hoffm.
- Usnea ceratina Ach.
- Usnea cornuta Körb.
- Usnea esperantiana P.Clerc
- Usnea filipendula Stirt.
- Usnea flammea Stirt.
- Usnea florida (L.) F.H.Wigg.
- Usnea fragilescens Hav. ex Lynge [38]
- Usnea fragilescens var. mollis (Vain.) Clerc
- Usnea fulvoreagens (Räsänen) Räsänen
- Usnea glabrescens (Nyl. ex Vain.) Vain.
- Usnea hirta (L.) F.H.Wigg.
- Usnea rubicunda Stirt.
- Usnea wasmuthii Räsänen
- Usnea wirthii P.Clerc
Text and images © Paul Whelan, 2009.



