(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).