(fi: naavat, sv: skägglavar)
Usnea sp.
Distribution in Finland
Common in southern and central Finland, sparse in northernmost Lapland.
Origin and general distribution
Widely distributed genus.
Growing form
Fruticose lichen (‘beard lichen’).
Size
Medium sized to large (usually < 20 cm).
Thallus
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.
Fruitbody
Apothecia rare in the Finnish species, with thalloid margin, hymenium pale brown.
Spores
Ascospores one-celled, hyaline.
Algal partner
Green alga (Trebouxia)
Habitat
In forests, especially in humid, but well lighted sites. Sensitive to atmospheric pollution.
Substrate
Predominately epiphytic, on acid bark of conifers and deciduous trees, more rarely on cliff faces.
Additional information
13 species in Finland (Vitikainen et al. 1997).
