Huilia Zahlbr.
Thallus crustose, heteromerous, thick, effuse or lacking. Photobiont green, Trebouxia. Apothecia lecideine, large, to 4 mm diam., black, with or without pruina. Excipulum well-developed, heavily carbonised in inner part. Hymenium colourless, to 160 µm tall. Paraphyses thin-walled, netted. Hypothecium brown-black. Asci with amyloid tholus or apical thickening, clavate, 8-spored. Ascospores medium to large (8-36 × 4-20 µm), ellipsoid, simple, colourless halonate when young.
Key
Huilia, a segregate of Lecidea sens. lat. , comprises c. 20 species in the family Lecideaceae. It is widely distributed and species are found mainly on acid rocks (rarely on basic rocks) at sea level and in mountainous areas, stream beds, debris of stone pavements and fellfield. Two species are known from New Zealand, but the genus remains to be properly studied and collected here. Huilia is related to Tremolecia, but is distinguished by the only partly carbonised excipulum. Useful information is found in Hertel [ Willdenowia 6 (2): 225-272 (1971); Beih. Nova Hedwigia 24: 63-69 (1967); Ergebn. Forsch. Unternehmens Nepal Himal. 6 (3): 200-225 (1977)].