Sticta weigelii
Thallus loosely attached, 4-15 cm diam., spreading or ± orbicular. Lobes very variable, broad and rounded to laciniate, lacerate, margins entire or slightly notched, incised, granular-isidiate, wavy to dissected. Isidia short, ± terete, granular becoming coralloid, often clustered, mainly marginal and there often dense, occasionally in clusters on upper surface along cracks or fissures. Upper surface greyish-brown to dark reddish-brown, smooth, matt, wrinkled or shallowly faveolate, rarely granular-isidiate. Lower surface pale brown to dark red- brown or ± blackened, with a dense, uniform, tangled, felt-like tomentum to margins. Cyphellae scattered to numerous, large, to 2 mm diam., white, rarely yellow-brown or reddish-brown, with a prominent, dark, raised rim. Apothecia not seen in New Zealand material.
N: North Auckland to Wellington. On trees and shrubs in moist, shaded humid situations, mainly lowland. Still poorly collected.
Pantropical
S. weigelii is a widespread tropical-subtropical lichen with a high degree of polymorphism reflected in a considerable array of subspecific taxa. As yet there is no satisfactory detailed definition of the species and the circumscription given above may itself represent several distinct entities. Until the species is properly delimited, it is understood as having a dark lower surface, a blue-green photobiont and clusters of marginal isidia. S. weigelii is distinguished from S. caliginosa in not possessing an anchoring holdfast or stalk and the thallus is not palmate. S. sublimbata is superficially similar but has soredia and not isidia. Much work is needed on this species both in New Zealand and elsewhere especially in tropical regions.
