Bispora betulina (Corda) S. Hughes, Can. J. Bot.

Kirschner, Roland, 2015, Phylogenetic placement of a new species of Corynesporopsis from dead acacia wood indicates occurrence of tretic conidiogenesis within Xylariales, Phytotaxa 192 (1), pp. 24-34 : 29-30

Bispora betulina (Corda) S. Hughes, Can. J. Bot. 36: 740 (1958) ( FIG. 5 )

Colonies on natural substrate dark brown, effuse. Hyphae pale brown, smooth, 2–4 μm wide, giving rise to closely aggregated conidiophores laterally or terminally on prostrate hyphae. Conidiophores mononematous, distinct from vegetative hyphae, simple, rarely branched at the base, irregular in shape and pigmentation, but mostly terminating in 1–3, rarely more, medium to dark brown cells separated by broad darkened septa, (14–)17–30(–34) × 4.5–5.5(–6) μm (n = 10). Conidiogenous cells apical, mono- to polyblastic or mono- to polytretic by minute apical pores or 1–1.5 wide, truncate or sometimes slightly concave conidiogenous loci, medium to dark brown, smooth, 5–7 × (4–)4.5–5.5 μm (n = 10). Conidia formed in predominantly unbranched, but sometimes branched chains, ellipsoidal to cylindrical, straight, broadly rounded at the ends, 0–5-septate (mostly 1–2-septate), smooth, medium to dark brown, at one or both ends with minute inconspicuous pore or 1-1.5 wide, truncate or slightly concave scar, 1-septate conidia (8.5–)10–12(–13) × (4–)5(–6) μm (n = 20), 2-septate conidia (13–)14–18(–19) × (4–)4.5–5.5(–6) μm (n = 20), 3–5-septate conidia appr. 14–30 × 5–5.5 μm.

In culture, hyphal ends often functioning as conidiophores so that it is difficult to clarify whether the conidiophore is much longer than on the natural substrate or only a short conidiophore arising terminally from the hypha. Other characteristics basically the same as on the natural substrate.

Material examined: — Dried culture, CANADA. Quebec, Hull, Quercus sp. , October 1960, G. L. Hennebert ( DAOM 71426 a), det. S. J. H. [= Hughes?], IMI 96728 ( K) ; on Populus tremuloides Michx. , CANADA. Manitoba, 1 m W Rennie , 26 July 1966, B. C. Sutton [ WINF ( M) 6498b], IMI 132937 ( K) ; on Fraxinus pennsylvanica , CANADA. Manitoba, Forest Research [Laboratory?], spruce woods, 22 April 1969, B. C. Sutton [ WINF ( M) 11219a], IMI 144736 ; dead wood of Fagus sylvatica, UK. Surrey, Esher Common , 16 September 1979, P. M. Kirk 462, IMI 241393 ( K) ; on wood of Quercus robur, UK. Devon, Exeter, Stoke Woods , 4 September 1978, P. M. Kirk 265, IMI 232050 ( K) ; on dead decorticated wood, U.S.A. New York, Warrensburg, Pack Forest , 3 October 1959, W. B. Kendrick ( DAOM 63877 ), IMI 78573 ( K) .

Notes: —Basically, the morphology on the natural substrate conforms to that described and illustrated by Ellis (1971) and Sutton (1969) and that from culture also to the morphology in culture shown by Matsushima (1985). In addition to these descriptions, predominantly the basal hilum of the conidia was somewhat truncate, 1–1.5 μm wide, whereas an inconspicuous pore was observed on the apex of the conidia and only occasionally appeared as a broader, sometimes even slightly concave scar. Although conidiophores were short and variable in structure and pigmentation, they were clearly distinct from vegetative hyphae by 1–3 more deeply pigmented cells separated from each other by darkened and broadened septa.

Figures

FIGURE 5. Bispora betulina, conidiophores and conidia. a. From natural wood substrate (IMI 78573, K). Scale bar = 10 μm. b. From agar plate culture (IMI 96728, K). Scale bar = 20 μm.