34 P. P. G. van den Boom Refercnces # L0;rm Figure 1. Protothelenella rylina, ascospores. Mayrhofer, H. & Poelt, P. 1985: Die Flechtengattung Microglaena sensu Zahlbruckner in Europa. Hercogia 7: 13- 79. <strong>GRAPHIS</strong> SCRIPTA 4 (Leez) Mayrhofer, H. 1987: Ergdnzende Studien zur Ta:
Caloplaca soropelta (8. S. Hansen, Poelt & Sgchting) Sgchting comb. nov. ULRIK SOcHTING Sochting, U. L992: Caloplacq soropelta (E. S. Hansen, Poelt & SOchting) Sochting comb. nov. Graphis Scipta 4: 35-36. Stockholm. ISSN 0901-7 Sg{' Caloplaca citina var. soropelta was described by Hansen, Poelt & SOchting (1987) from Greenland. Subsequent finds from Svalbard has proved th; ta:ron to be well delimited from C. ci.trina and it is accordingly heie raised to species level. New material, which is partly fertile, allows 1o make a more comprehensive description, and thus to establish a better understanding of the species. UMk Sochting, _In1tltut for Sporeplanter, University of Copenhagen, O. Faimagsgade 2D, DK-1353 Copenhagen K. Caloplaca soropelta €. S. Hansen, poelt & Sgchting) SOchting comb. nov. Basionym: Caloplaca citrina var. soropelta E. S. Hansen, Poelt & Sochting. l9g7; Meddr. Gr^nland Biosc. 25: 26. Morphology Thallus up to 2 cm in diameter, consisting of centrally crowded, laterally dispersed, irregular, but hardly incised squamules, which are up to about I mm, bright orange yellow to bright golden yellow and often slightly pruinose. fhe squamules are peltate in the centre, but smaller, more convex and more appressed to the substratum towards the periphery of the thallus. Older squamules are concave, with often greyish cortex, and most often golden yellow soralia developing from the under surfgce of the periphery. soralia never develop at the surface of the squamules, which remain covered by a strongly concave cortex. Soredia 20-30pcm diam. Apothecia lecanorine to zeorine, very rare and unripe in the material. They are sessile centrally on the squamules, at the material studied about 0.6 mm diam. Disc initially concave, orange. The margin is about 0.1 mm thick, concolorous with disc. The outer surface of the margin is sorediate. Anatomy Cortex thin, little differentiated. Algal layer about 300 pm thick, diffuse. A fine epipsamma of anthraquinones is very abundant at the soralia, less so on the cortex. Thalline margin with many algae producing soredia laterally. Hymenium immature, but paraphyses seem to be little branched and hardly inflated apically. Ecologr Caloplaca soropelta is a species of highly eutrophicated, calcareous rock. It prefers cracked surfaces. on rocks with soil accumulated in the cracks it may form peltate squamules with rhizinae penetrating the soil. c. soropelta is often associated with xanthoria elegans, X. sorediata, X. candelaria, Caloplaca sacicola and C. decipiens.