Usnea intermedia (A. Massal.) Jatta

Nomenclatural data
Flora Ital. Cryptog. 3: 145 (1909)—Usnea barbata var. intermedia A. Massal., Schedul. Critic. 3: 62 (1856).—Usnea carpatica Motyka, Lich. Gen. Usnea Stud. Monogr., Pars Syst. 2(1): 469 (1937)—Usnea faginea Motyka, Lich. Gen. Usnea Stud. Monogr., Pars Syst. 1: 172 (1936)—Usnea glauca Motyka, Lich. Gen. Usnea Stud. Monogr., Pars Syst. 1: 167 (1936)U. hapalotera (Harm.) Motyka, Lich. Gen. Usnea Stud. Monogr., Pars Syst. 1: 235 (1936)—Usnea harmandii Motyka, Lich. Gen. Usnea Stud. Monogr., Pars Syst. 1: 163 (1936)—Usnea montana Motyka, Lich. Gen. Usnea Stud. Monogr., Pars Syst. 1: 234 (1936)—Usnea neglecta Motyka, Lich. Gen. Usnea Stud. Monogr., Pars Syst. 1: 179 (1936)—Usnea protea Motyka, Lich. Gen. Usnea Stud. Monogr., Pars Syst. 1: 232 (1936)—Usnea quasirigida Lendemer & I.I. Tav., Proc. Acad. Nat. Sci. Philadelphia 153: 179 (2003).—Usnea rigida Motyka, Lich. Gen. Usnea Stud. Monogr., Pars Syst. 1: 177 (1936), nom. illeg., non Usnea rigida Vainio (1901).—Usnea smaragdina Motyka, Lich. Gen. Usnea Stud. Monogr., Pars Syst. 1: 161 (1936).
Morphology
For a detailed description, see Clerc (1984, 2007) and Halonen et al. (1998). Thallus shrubby to pendent; base pale or blackened; branches are irregularly swollen and may have foveoles and depressions on the surface; fibrils numerous; papillae abundant, verrucose or cylindrical; soralia and isidiomorphs absent; apothecia frequent, arising at apices of primary and secondary branches, with long marginal projections; ascospores 7–8.5 μm long. Cortex thin; medulla thin, loose.
Medullary chemistry
Chemotype (1) with salazinic acid (K+ yellow to red, Pd+ orange) as a main substance is known in Europe; chemotype (2) with protocetraric acid (K–, Pd+ orange) as a main substance is known in North America (Halonen et al. 1998); chemotype (3) without medullary compounds (K–, Pd–) has also been reported from North America (Clerc 2007).
Remarks
Differs from another fertile European taxon, U. florida, by subpendent to pendent thallus, medullary chemistry and shorter ascospores (8–11 μm long in U. florida).
Click on images to see more!
Ecology and distribution
Europe (map legend)
Corticolous. Reported in Europe: Austria, Bulgaria, Czech Republic, Germany, Italy, Poland, Slovakia, Slovenia, Spain, Switzerland, Ukraine.