Parmeliella parvula
Description : Thallus minutely squamulose. Squamules 1–2 mm long, ±elongate and indented, crenulate, flat or concave, pale blue-grey, rarely tinged fawnish, scattered or ±contiguous, forming small patches or a ±continuous crust-like cover on substratum. Soralia marginal and laminal, often ±rounded, crateriform, becoming confluent and covering large parts of thallus, soredia coarsely granular–isidiate. Apothecia very rare (not seen in NZ material), to 0.5 mm diam.; disc pale red-brown to blackish, with a persistent, paler proper exciple, often becoming ±convex. Ascospores ellipsoidal, with a minutely warted epispore, 15–18 × 6–7 μm.
Chemistry : TLC−, all reactions negative.
N: Northland (Te Paki Bush). In coastal forest, still very poorly collected and known in NZ. Also known from Great Britain, Ireland, Norway, Portugal, Italy Macaronesia, Tristan da Cunha and North America, in cool temperate regions of both hemispheres (Jørgensen 1977: 19; 1978: 37–38; 2000d).
Bipolar
Illustrations : Jørgensen (1977: 19, fig. 3; 1978: 35, fig. 13; 2000d: 697, fig. 46); Thor & Arvidsson (1999: 298); Dobson (2000: 277; 2005: 304).
Parmeliella parvula is a minute species, visible as a bluish flush on branches and to see it properly a lens is required. The thallus, although tiny, is well developed and consists of tiny greyish blue, scabrous squamules not more than 1–2 mm in diam. They are distinctly lobed and grow directly on bark or other lichens with no visible prothallus. The crateriform soralia are distinctive in being located on the surface of the thallus and not at the margins as in other sorediate taxa in the Pannariaceae.
