Mycotaxon 33: 401 (1988).

Basionym: Parmelia conspersa var. angustiphylla Gyeln., Feddes Rep. 29: 153 (1931).

Type: Hungary, Nógrád, Diosjenö, Mt. Csóvanyos, 24.4.1926, Gyelnik (BP - lectotype).

Thallus: adnate to loosly adnate, 3-10 cm diam., rather firm, often pulvinate. Lobes subirregular to sublinear, elongate, subascending, flat to subconvex, separate and often forming an imbricate mat, 0.8- 1.5 mm wide, dichotomously branched, contiguous to densely imbricate, often densely lobulate and laciniate, the laciniae 0.3- 0.5 mm wide; upper surface dull to shiny yellowish green, smooth, emaculate; soralia and isidia lacking; lower surface smooth, black, moderately rhizinate; rhizines black, simple, 0.2- 0.8 mm long. Apothecia common, substipitate, with a thin, smooth, thalline exciple, 3-10 rmn wide; disc reddish brown. Spores ellipsoid, 9-10 x 5- 6 μm. Pycnidia common, laminal. Conidia dumbbell-shaped, 5- 6 x 0.5 μm.

Photobiont: Trebouxia.

Chemistry: Cortex C—, K—, KC+ yellow, PD-, HNO,—, UV—; usnic acid. Medulla C—, K+ ye1low—orange, KC+ orange-red, PD+ orange, UV—; stictic, constictic, hypostictic and norstictic acids together with traces of cryptostictic and peristictic acids (chemistry identical with that in X. conspersa).

Ecology: Saxicolous on siliceous rocks.

Molecular data: Genbank

Distribution: Circumpolar Northern Hemisphere. Rather rare in northern and eastem Europe, more common in eastern North America.

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