Parmeliella nigrata
≡Pannaria nigrata Müll.Arg., Bull. Herb. Boissier 4: 91 (1896).
Description : Thallus small-foliose to squamulose, in neat rosettes to straggling–irregular, 0.5–3 cm wide, on a thin to thick, ±byssoid prothallus projecting to 4 mm beyond squamules. Squamules 1–3 mm wide, irregularly laciniate to stellate or cochleate. Margins slightly thickened to lobulate–isidiate. Upper surface smooth to lightly furrowed or fissured in parts, somewhat leathery to minutely crystalline–scabrid in parts, isidiate, pale to dark grey-blue. Isidia simple, digitate at first, soon becoming ±coralloid, 0.2–0.5 mm tall, 0.1 mm wide, swollen at apices, marginal and laminal, often forming a central diffract crust obscuring thallus and apothecia, concolorous with thallus or paler. Apothecia rounded or contorted, occasional to frequent, 0.3–1.2 mm diam., often ±immersed in isidiate crust; disc concave, becoming plane to subconvex, pale to dark red-brown; proper exciple prominent, slightly raised, entire, concolorous with disc or paler. Ascospores ellipsoidal, 10–15 × 7– 8 μm.
Chemistry : TLC−, all reactions negative.
N: Northland (Fanal I., Hen I., Little Barrier I.), South Auckland (Te Aroha). S: Westland (Lake Kaniere). A species of lowland rainforest, in humid, shaded habitats along stream margins. On bark of Kunzea ericoides and sometimes on leaves of Pseudowintera colorata. Also in SE Australia and Brazil (Jørgensen & Galloway 1992: 277; Aptroot 2002e; McCarthy 2003c, 2006).
Austral
Parmeliella nigrata is characterised by: the corticolous (rarely foliicolous) habit; irregularly laciniate to stellate or cochleate squamules, 1–3 mm wide, pale to dark grey-blue and in parts crystalline–scabrid; simple to coralloid isidia at margins and spreading centrally to form a diffract-areolate crust; apothecia immersed in isidiate crust, disc pale to dark red-brown, with a prominent, entire proper exciple, concolorous with disc or paler; and ellipsoidal ascospores, 10–15 × 7–8 μm.
