Dichotomous key to European Rosellinia

           

Subgeneric classification and ascospores dimensions follow Petrini (1993), and Laess°e & Spooner (1994) for R. evansii. Owing to variations reported in subiculum persistence in R. glabra and ambiguous features in R. helvetica, they both appear in two different sections of the key.

 

Key to subgenera and related taxa
1- Subiculum absent from the earlier stages onwards 2
1- Subiculum present around perithecia, at least at young stages 4

 
2- Stromata erumpent,  with bark rupturing in a stellate pattern, ascospores 22-28 x 8.5-10 Ám with a spiralling germ slit R. evansii

2- Stromata superficial 3

 
3- Stromatal surface with conspicuous cracks, ascospores 19-26 x 6-8.5 Ám with short sigmoid germ slit; on dicotylodenous hosts R. callosa
3- Stromatal surface smooth, ascospores 15-22 x 5.5-9 Ám, with a straight  germ slit spore-length; bambusicolous R. amblystoma
 
4- Subiculum non-persistent, absent around mature stromata subg. Calomastia
4- Subiculum persistent, at least at the base of mature stromata 3
 
5- Ectostroma thin (< 25 Ám thick), brittle, folded at the base when dry subg. Corrugata
5- Ectostroma thicker, hard, smooth to rugulose subg. Rosellinia

 

Key to species of subgenus Rosellinia.
1- Ascospores with a germ slit much shorter than the spore length 2
1- Ascospores with a germ slit nearly spore-length 3
 
2- Ascospores 20-30 x 6-8.5 Ám; restricted to Buxus R. buxi
2- Ascospores 33-43 x 5.5-7.5 Ám; plurivorous R. necatrix
 
3- Ascospores lacking cellular appendages 4
3- Ascospores with one or two cellular appendages 5
 
4- Ascospores 19.5-23.5 x 7-9 Ám, with a slimy sheath on the flattened side and at both ends R. helvetica
4- Ascospores 14-17.5 x 5.5-8 Ám, without slimy sheath R. saccardii
 
5- Ascospores 20-28 Ám long, with one or two cellular appendages and a slimy sheath around the whole spore R. corticium
5- Ascospores 14-23 Ám long, with two cellular appendages, and slimy caps at both ends 6
 
6- Stromata averaging 1.3 mm diam x 1.1 mm high; ascospores 15-23 x 6.5-9 Ám R. aquila
6- Stromata averaging 0.8 mm diam x 0.7 mm high; ascospores 14-18 x 5.5-7.5 Ám R. glabra

 

Key to species of subgenus Corrugata
1- Ascospores with a germ slit much shorter than the spore length 2
1- Ascospores with a germ slit nearly spore-length 3
 
2- Ascospores 22-32 x 6-8.5 Ám, with 2 pointed appendages R. desmazieresii
2- Ascospores 16-23 x 5-8 Ám, with 1 blunt cellular appendage R. mycophila
 
3- Ascospores with 1(-2) blunt cellular appendage and a thick slimy sheath; ascospores 21.5-28.5 x 9.5-12.5 Ám R. diathrausta
3- Ascospores with 2 spiny cellular appendages, lacking a slimy sheath 4
 
4- Ascospores 17-26 x 6-9 Ám R. thelena
4- Ascospores 13.5-17.5 x 5-7 Ám R. thelena var. microspora

 

Key to species of subgenus Calomastia
1- Ascospores with germ slit sigmoid and much shorter than spore length R. franciscae
1- Ascospores with germ slit straight on only slightly sigmoid, spore-length 2
 
2- Ascospores lemon-shaped R. medullaris
2- Ascospores ellipsoid to ellipsoid-inequilateral 3
 
3- Ascospores with a slimy sheath on the flattened side and at both ends, cellular appendages absent 4
3- Ascospores with slimy caps only at both ends, cellular appendages present or not 6
 
4- Stromata with conical top; subiculum somewhat persistent, ascospores 19.5-23.5 x 7-9 Ám R. helvetica
4- Stromata flat-topped; subiculum non-persistent 5
 
5- Ascospores 16-21 x 6-8 Ám, ascal apical apparatus up to 5 Ám high R. mammaeformis
5- Ascospores 20.5-26.5 x 6-9 Á, ascal apical apparatus up to 8 Ám high R. britannica
 
6- Ascospores with cellular appendages at both ends 7
6- Ascospores lacking cellular appendages 8
 
7- Ascospores brown to dark brown, 14-18 x 5.5-7.5 Ám R. glabra
7- Ascospores light brown, 19.5-29.5 x 5.5-8.5 Ám R. subsimilis
 
8- Ascospores 14-16.5 x 5.5-7.5 Ám R. etrusca
8- Ascospores longer 9
 
9- Ascospores narrowly ellipsoid in front view, 17-27 x 5-7 Ám R. nectrioides
9- Ascospores broadly ellipsoid in front view, 16.5-24.5 x 5.5-8.5 Ám R. abscondita