Boletus caucasicus
Boletus caucasicus Alessio
Boletaceae
Conservation status. Critically Endangered [CR B1ab(iii)+2ab(iii)].
Morphology and biology. Cap up to 10 cm in diameter, convex to nearly flat, greyish brown or yellowish brown with reddish spots, blueing when bruised. Stipe central, cylindrical or clavate, in the upper part yellow, yellowish orange to red elsewhere, in the upper half with red defined network, in the lower half with fine granules; surface blueing when bruised. Flesh lemon yellow, blueing when exposed to air. Tubes yellow, pores red or orange red, blueing when bruised. Basidiospores 13–16 × 5–8 μm. Mycorrhizal with broadleaf trees.
Habitats and populations. Light thermophilous oak forests close to the seashore. Found only once in 1977 and since then not confirmed despite of the extensive search.
Distribution in Bulgaria. Black Sea Coast (Northern); up to 100 m.
General distribution. W, C and S Europe, Caucasus.
Threats. Forest cutting, habitat loss and degradation due to intensive tourism and infrastructure development.
Conservation measures taken. Included in the Red List of Fungi in Bulgaria. The locality is situated in a site of the European ecological network Natura 2000 in Bulgaria.
Conservation measures needed. Sustainable management and conservation of the habitat and of the known locality.
Note. Close to B. luridus Schaeff. : Fr., from which it is distinguished mainly by its yellow flesh under the tubes and the negative amyloid reaction of the hyphae.
References. Engel et al. 1983; Alessio 1985; Kuthan & Kotlaba 1989; Denchev & Assyov 2010.
Authors: Boris Assyov, Cvetomir M. Denchev
