Pezizaceae Dumort.

UPDATED KEY TO THE SPECIES OF MaRceLLeiNa BRUMM., KORF & RIFAI AND ALLIED GENERA

This key is based on the work of Moravec (1987) and applies to small discoid to pulvinate species, rather thick, showing violet, purple-brown, brown to black ascomata, and having globose ascospores containing at least one oil drop.

1. Ascus wall amyloid, sometimes weakly, best seen in the young asci.............................................................. 2

— Ascus wall always inamyloid........................................................................................................................ 3

2. Ascomata brownish, dark brown to blackish, sometimes with olivaceous shades, without purplish tinges; ascospores 7-8.5(9) µm diam., ornamented with large, angular warts............................................................................................ Scotopezia pseudoanthracina (Donadini) Van Vooren, Sammut & P. Alvarado, comb. nov.

— Ascomata black; ascospores 9.5-11.9 µm diam., smooth................. Iodomarcelleina obscura gen. nov., sp. nov.

3. Ascospores ornamented, uniguttulate, but often accompanied by smaller droplets...................................... 4

— Ascospores smooth, uniguttulate, rarely accompanied by smaller droplets................................................... 8

4. Ascospore ornamentation forming a complete or incomplete irregular reticulum........................................ 5

— Ascospore ornamentation made of isolated warts or curved irregular ribs which only rarely anastomose, appearing as ribs or spines in optical section; ascospores more than 8 µm diam..................................................... 6

5. Ascospore reticulum mostly complete, only rarely incomplete, relatively low in optical section; 9-11 µm diam.......................................................................... Marcelleina persoonii (P.Crouan & H.Crouan) Brumm.

— Ascospore reticulum mostly very incomplete, only very rarely complete, irregular, comparatively higher in optical section; 8-10.7 (11) µm diam.......................................................................... M. rickii (Rehm) Graddon

6. Ascospore ornamentation made of large warts, ± rounded or tuberculate in optical section; ascospores 12-16 µm diam........................................................ M. tuberculispora K.Hansen & Sandal (synonym: M. mediterranea)

— Ascospore ornamentation made of smaller warts or ribs, rather low in optical section................................. 7

7. Isolated warts and ribs 0.25-0.8(1.4) µm thick, 0.3-0.7(1) µm high; paraphyses enlarged above; ascospores (8)9-11 µm diam.............................................................................................. M. georgii (Svrček) J.Moravec

— Isolated warts and ribs coarser, 0.5-1.5(2.2) µm thick, 0.5-1.5(1.7) µm high; paraphyses not or very slightly enlarged above; ascospores (8)9-11 µm diam................................................... M. brevicostatispora J.Moravec

8. Ascomata violet to dark violet; ascospores 10-12 µm diam......................................... M. benkertii J.Moravec

— Ascomata light to dark brown; ascospores 14-18 µm diam................ M. chopraiana (L.R.Batra) S.C.Kaushal