A New Combination for a Newly Recorded British Bolete

Abstract

Identification of the xerocomoid boletes has always been critical and it was only after the recent description of Xerocomus cisalpinus (Peintner et al. 2003) that it was realised this fungus might have been found in Britain but passed over as an aberrant member of the Boletus chrysenteron consortium. Xerocomus cisalpinus has been found extensively in Italy associated with Quercus spp., although not as yet with Q. robur and Q. petraea, and with Fagus sylvatica. Examination of fresh and suspect dried specimens and re-evaluation of other herbarium material indicated the presence of the tell-tale characters of this species, viz. a pileus suprapellis differing from that of B. chrysenteron Fr., slightly longitudinally striate and rather narrow basidiospores and amyloid 'pruinatus' hyphae, an unusual hyphal type described by Ladurner & P6der (2000) in the stipe tissue of Boletus pruinatus Fr. & Hok. The British collections now recognised as belonging to this taxon range from Derbyshire (Ousledene, Clough Derwent, 7 Sept. 2003, Herb. A. Hills, Oxford) in the north to Berkshire (Silwood Park, 16 Sept. 2003, in Herb. K, K(M) 120369), Oxfordshire (Grey's Green Village Green, nr Henley, 13 Nov. 2002; Herb. A. Hills) and West Sussex Park (Wakehurst Place, 9 Nov. 2003; Herb. K, K(M) 120269) in the south and Shropshire (Attingham Park, 17 Oct. 2003; Herb. K, K(M) 120027) in the west. All the collections were associated with Quercus spp. and/or mixtures of Quercus and Fagus, except the collection from Silwood Park which appeared to be associated with Cedrus. It is possible that now it has been recognised it will be found to have a much wider distribution.