Usnea

Fruticose lichen (‘beard lichen’).

Medium sized to large (usually < 20 cm).

Lobes narrow, richly branched, bushy erect to long pendent, thallus attached to substrate by single holdfast. Main branches with numerous short side branches (fibrillae) and with an internal, strong, pale central strand. Cortex often with wart-like outgrowths (papillae). Many species produce soredia or isidia.

Apothecia rare in the Finnish species, with thalloid margin, hymenium pale brown.

Ascospores one-celled, hyaline.

Green alga (Trebouxia)