Flavoplaca citrina (Hoffm.) Arup, Frödén & Søchting

Nordic J. Bot. 31, 1: 36 (2013).

Basionym: Verrucaria citrina Hoffm., Deutschl. Fl., Zweiter Theil (Erlangen): 198 (1796) [1795].


Protolog: Data lacking.

Protolog type data: Data lacking.

Type locality: Data lacking.

Type locality coordinates: Data lacking.

Molecular barcode: Data lacking.

Thallus: crustose, up to 5 mm diameter, endoxylic or as scattered, thin, 0.2 mm large, orange yellow areoles, which soon erupt and are transformed into bright golden yellow, irregular, up to 0.4 mm large soralia. Single scattered soralia may occur on the substrate. Soredia 25-35 µm large. Apothecia are very scarce on lignum, but more common on near-by pepples. They ate up to 0.6 mm diam., few on each thallus, sessile among the soralia. Disc orange yellow, more orange than the areoles and the soralia, plane to slightly convex. Marginthin, 60 µm, regular, slightly prominent or more often level with disc, soon depressed, concolourous with the areoles. Amphithecium with few algae in a conglutinated, paraplectenchymatic medullary tissue, with about 4-5 µm large lumina. Cortex poorly developed. Basic part of the apotecium eith crystalline fine granules on hyphae, I+ slightly violet. Parathecium poorly developed, narrowly fan-shaped. 50 µm broad, laterally paraplectenchymatic, with 6-7 µm large cells. Outer 10-15 µm with inspersed, fine, yellow epipsamma. Hypothecium 20-30 µm, consisting of conglutinated, intricately interwoven hyphae, with many oil droplets. Hymenium 80 µm, with fine yellow epipsamma. Paraphyses apically branched, inflated, up to about 5.5 µm thick. Ascospores: Asci with 8 spores. Spores 10-12 x 7-8 µm. Septum about 3 µm thick (Søchting 1989: 249).

Photobiont: green, coccoid, up to 16 µm in diameter (Tønsberg 1992: 116).

Chemistry: Parietin (major), several other anthraquinones (Santesson 1970). Amphithecium I+ (xx). Parietin. Orange parts K+ purplish (Tønsberg 1992: 116).

Ecology: Base of trunks of Acer platanoides and Ulmus glabra (Tønsberg 1992: 116).

Molecular data: Genbank

Distribution: Database