Opegrapha sphaerophoricola sp. nov.

Abstract

A new lichenicolous fungus, Opegrapha sphaerophoricola Isbrand & Alstrup, is described from Sphaerophorus globosus in North America. Opegrapha is a genus comprising lichenized as well as lichenicolous fungi. The family Opegraphaceae has recently been investigated for the Mediterranean area (Torrente & Egea 1989), but many of the lichenized species in Northern Europe are still insufficiently known and a revision is highly needed. The lichenicolous species are much better known, and a key to these was published by Clauzade et al. (1989). One additional new species on Stereocaulon has recently been described (Alstrup & Hawksworth 1990). However, some lichenicolous fungi presently placed in the genus Leciographa may have to be incorporated in Opegrapha. The known lichenicolous species of Opegrapha are found on a variety of lichen genera, e.g., Brigantiaea, Clathroporina, Dermatocarpon, Lecanora, Parmelia, Pertusaria, Phaeorrhiza, Thelotrema, Staurothele, and Xanthoria. The genus has a worldwide distribution. The new species described here was collected by the first author during a holiday, which also included sporadic collecting of lichens in diverse habitats in British Columbia and adjacent parts of the United States. OPEGRAPHA SPHAEROPHORICOLA Isbrand & Alstrup sp. nov. (FIG. 1-4) Fungus in lichene parasiticus. Ascomata nunc dispersa, nunc aggregata, plus minusve connata, tumuliformia, valde convexa, e verticibus visa rotundata, non ramificata, sessilia vel basibus immersa, nigra, ad circiter 1 mm diam. Epithecium 5-10 Atm altum, fusco-nigrum; hymenium 6070 Atm altum, achroum, hyalinum; hypothecium fusconigrum, 50-60 Atm altum, pseudoparenchymaticum, e cellulis compositum rotundatis vel angulatis, 6-8 tm diam. Excipulum sensim in hypothecium transiens, initio hymenium paene tegens, post dilatatum. Paraphyses ramificatae, anastomosantes, 2 tm crassae. Asci clavati vel anguste clavati, fovea interna apicali rostriformi in tholum impressa, 50-65 x 13-16 Am magni, octospori. Ascosporae anguste ellipsoides, ad apices rotundatae, ternis septis divisae, initio achroae, hyalinae, aetate provecta substantia obscura extra irregulariter deposita pictae, 19-22.5 x 5.5-6 Am magnae. Nullae partes jodo coloratae, nec recentes nec 10% KOH tractatae. HOLOTYPUS: CANADA. BRITISH COLUMBIA. Vancouver Island, Kennedy River, ca. 5 km from the outlet to Kennedy Lake, between road no. 4 and the river, on Sphaerophorus globosus growing on Alnus sp. close to the river, 3 May 1989, S. Isbrand (c). Lichenicolous fungus. Ascomata dispersed to aggregated-stromatic, rounded, not branched, strongly convex, sessile or immersed at base, base not constricted, black, to about 1 mm diam.; epithecium 5-10 im high, brown-black; hymenium 60-70 im high, hyaline, hypothecium brown-black, 50-60 im high, pseudoparenchymatic, cells rounded to angular, 6-8 im diam.; exciple contiguous with hypothecium, when young almost covering the hymenium, later expanding; paraphyses branched and anastomosing, 2 im thick; asci clavate to narrowly clavate, with a tholus with an internal apical beak,