Lasallia Mérat
Thallus heteromerous, foliose, dorsiventral, monophyllous, attached to substrate by a ± central umbilicus. Lobes entire, strongly dissected, pliable and somewhat leathery when wet, brittle when dry. Upper surface pustulate, pustules ± convex, round or oval, marginal or ± central, ± pruinose, cracked or lacerate, brown, dark brown, grey-brown or greyish, rarely reddish, with or without isidia, soredia or verrucae. Photobiont green, Protococcus. Lower surface lacunose, lacunae corresponding to pustules of upper surface, smooth or verrucose, without rhizines. Apothecia lecideine, sessile to pedicellate, disc plane, smooth or irregular, margins persistent. Ascospores 1 (rarely 2) per ascus, large, muriform, pale to dark brown.
Lasallia is a genus of c. 12 cosmopolitan species included in the family Umbilicariaceae. [Llano Monogr. Lich. Fam. Umbilicariaceae: 27-48 (1950); Krog Bryologist 76: 550-554 (1973); Frey in Poelt, Ergebn. Forsch. Unternehmens Nepal Himal. 6: 387-395 (1976)]. An undescribed species somewhat similar to L. sinensis Vej, is known from Silver Peak near Dunedin, but the material is fragmentary and sterile. The genus should be looked for in alpine regions of South I., especially east of the Main Divide on the foothill ranges of Otago, Canterbury and Marlborough.
