Usnea hirta  

Thallus 1-4 cm tall, ± tufted, erect, shrubby or rarely subpendant, notably flaccid when wet, main branches to 1 mm diam, angular or irregular (not round) in cross-section, ± slightly swollen. Surface often with inconspicuous, net-like ridges surrounding ill-defined depressions, richly branched, papillae absent, fibrils few or absent, grey-green, yellow-green or blackish grey, not blackened at the base. Isidia abundant, scattered or densely clustered, short and spinule-like, sometimes arising from the ridges. Cortex thin, medulla rather lax, axis relatively thin.

Anamorph: not known.

Teleomorph: ascomata (apothecia) rarely seen.

Chemistry: thallus C–, K–, KC–, Pd– (usnic and ± fatty acids [murolic acid complex]); reported K+, Pd+ specimens are probably due to contamination.