Picture taken on the 9th April 2007 at "Gorges du Segre" near Bains de Llo, Llo, Oriental Pyrenees, France, on siliceous rock rich in iron, West exposure, vertical surface 90 º, water-track, very damp place, 1380 m. altitude, associated to Acarospora sinoptica.
General view of the imperfect stage, being very common to find it that way. Sterile thallus. It is important to mature these forms when involved in the study of lichen associations and I suggest lichenologysts to publish more photos of the imperfect stages.
See picture in "BioImages:The Virtual Field-Guide (UK)"