Hypotrachyna rockii (Zahlbr.) Hale
Parmelia rockii Zahlbr., Annls mycol. 10: 379 (1912).
Thallus lobate, loosely attached, 5-12 cm diam., corticolous. Lobes sublinear 1-6 mm wide. Upper surface plane, shining, often distinctly white-maculate (×10 lens), whitish mineral grey, sorediate. Soralia pustular, orbicular, subterminal. Medulla white, pale orange below soralia. Lower surface black, densely rhizinate. Rhizines black, squarrosely branched, to the margin. Apothecia not seen. Chemistry: Cortex K+ yellow; medulla K-, C+ rose, KC+ rose, Pd-. Lecanoric acid and atranorin.
N: Auckland (Karekare Beach, Waitakere Ra., on coastal rock). S: Nelson (Lake Rotoiti, on bark of Hebe elliptica on the lake shore).
Cosmopolitan
