A juvenile fruiting body of Boletus aereus Bull. ex Fr. em. Quél. was found in a Quercus-Carpinus forest on the north slope of Javorka Hill near Karlštejn on July 14, 1963. This species had not previously been recorded in the area known as "Český kras".
Pouzar Z. (1964): Boletus aereus Bull. ex Fr. em Quél. in localitate nova regioni carsticae bohemicae „Český kras“ dictae lectus. – Česká Mykologie 18(1): 16–18.