Micarea confuse, a species easily confused with M. denigrate, is described from heavy-metal contaminated ground in Belgium and The Netherlands. Additional information is provided on the main locality at Budel-Dorplein.

Bacidia caesiovirens S. Ekman & Holien sp. nov. is described from Norway, and the British Isles. It occurs on trunks of deciduous trees in coastal forests. This species is usually sterile and is characterized by its conspicuously blue-green, granular thallus, which contains a bluish, N+ purple pigment. It is closely related to B. biatorina (Körb.) Vain., but differs from this species in a number of features apart from thallus pigmentation: the thallus granules are smaller, the amount of hyphal projections from the surface of the thallus granules is larger, and the internal pigmentation of the apothecia is different. Bacidia auerswaldii (Hepp ex Stizenb.) Mig. has a similarly granular thallus but differs from B. biatorina and B. caesiovirens in having wide, fusiform spores and smaller thallus granules. Bacidia absistens (Nyl.) Arnold has an internal apothecium pigmentation similar to B. caesiovirens, but differs in having a smooth thallus, and an abundance of minute crystals in the excipulum.

The monotypic lichen genera Aphanopsis and Steinia have various ecological and anatomical features in common. Both genera exhibit a particular ascus type and are recognized as representing a family of their own, the Aphanopsidaceae. This family is preliminarily placed in the order Lecanorales.

Ten species and one variety of Verrucaria Schrader are known from creeks and rivers in eastern Australia. Verrucaria austroalpina sp. nov., V. inconstans sp. nov., V. mundula sp. nov., V. mundula var. deminuta var. nov., V. phaeoderma sp. nov., V. tasmanica sp. nov. and V. tholocarpa sp. nov. are described. The combination V. puncticulata (P. M. McCarthy) P. M. McCarthy is made for V. hydrela var. puncticulata P. M. McCarthy. Verrucaria margacea (Wahlenb.)Wahlenb. and V. praetermissa (Trevisan) Anzi are reported from the Southern Hemisphere for the first time.

The taxonomy of the foliicolous members of Arthoniaceae (Anhonia, Arthothelium, Cryptothecia, Eremothecella) in Costa Rica is revised. Cryptothecia farkasiae sp. nov. is described, being closely related to Stirtonia sprucei, and bearing pycnidia reminiscent of Eremothecella. Anhonia lividofusca is placed in synonymy with A. aciniformis. Pycnidia and pycnospores are further described for Anhonialeptosperma, A. cyanea, A. palmulacea, A. trilocularis, Anhothelium cingulatum, Stinonia sprucei and S. macrocephala, and campylidia were found on thalli of Anhonia aciniformis. Anhonia nigratula and Cryptothecia Candida are reported for the first time from Costa Rica, and new localities are given for previously reported species. Ecological data are provided, and the relationships between foliicolous members of the Arthoniaceae are discussed.

Thalli of Ramalina capitata were sprayed with deionized water, 10 mM solutions of KNO3 or NH4Cl, or maintained without any water supply, for 10 days under controlled conditions. The lichens without a water supply showed an increase n antheraxanthin, lutein and β-carotene. The samples treated with deionized water showed a significant increase in violaxathin, antheraxanthin and β-carotene. The lack of a significant difference in zeaxanthin could indicate the absence of de-epoxidation of violaxanthin to zeaxanthin via antheraxanthin. Those samples treated with nitrate solution showed a significant increase in all pigments except for antheraxanthin. In contrast, ammonium treatment did not induce changes compared to water alone, except that antheraxanthin decreased. The lichens treated with nitrate exhibited a significant increase in both chlorophyll a and chlorophyll b, but ammonium affected only chlorophyll b.