Addendum to the typification of Butyriboletus regius.

In our previous paper (Janda et al. 2019), Krombholz’s colour plate number 7 of Butyriboletus regius (Krombh.) D. Arora & J.L. Frank was designated a lectotype for the name of this species. From the technical point of view, the illustrations published in his work (Krombholz 1832) are hand-coloured lithographs (Stafleu & Cowan 1979, Šebek 1983). During our ongoing examination of the iconography of B. regius we have found some dissimilarities between particular copies of Krombholz’s work, regarding not only the “position, presence and absence of contents, indexes, errata” (Stafleu & Cowan 1979: 679), but also the colour rendering. The reason is that uncoloured lithoprints were handed over to different illustrators, i.e. craftsmen who coloured them (Šebek 1983). Consequently, plates slightly vary in overall colouring and some other details (and, interestingly, some copies contain mirror-reversed tables). For example, the colour of the pilei in plate 7, fig. 1 is darker in some copies (e.g. in the library of Department of Botany of the Moravian Museum in Brno, signature III126/18372), while it is lighter in others (e.g. in the library of the Mycological Department of the National Museum in Prague, signature 41A62). The olive tint on the pilei in plate 7,