Pore width inHeterobasidion annosum(Fries) Brefeld

Abstract

Pores in 45 basidiomata of Heterobasidion annosum from New Zealand (26) and Australia (19) were significantly larger (P < 0.01) than those in 31 fructifications from North America (including 30 from British Co.lumbia) and 49 fructifications from Europe (includmg 44 from Finland). The mean distance along lines of 10 contiguous pores was 4.7 mm (range 3.7–5.8 mm) for New Zealand collections; 4.9 mm (3.8–5.9 mm) for Australian collections; 2.5 mm (1.7–3.3 mm) for collections from North America; and 2.4 mm (2.1–2.8 mm) and 3.1 mm (2.6–3.6 mm) for collections belonging to two intersterility groups (“S” and “P”) from Europe. The fungus in Australasia is therefore taxonomically distinct from forms of H. annosum present in the Northern Hemisphere.