Among the treasures of the Komarov Botanical Institute at St. Petersburg is a folio known as “Thunberg Icones Plantarum Japonicarem (ineditae)”. This volume contains 305 fine drawings, washed grey apart from a few that are in watercolours. Actually, known can hardly be said; like so many bound collections of pictures only a few of the institutions’ staff members with a special interest in history know of its existence, still less have ever seen it. Good photographs of these drawings (natural size, that is 37 x 26 cm) form the kernel of this work. Added are Maxomiwicz’s notes on the drawings (the great Russian 19th century botanist Maximowicz with his special interest in the East Asian flora brought some important historical collections on Japanese botany to the herbarium of St. Petersburg, including also the present volume); photographs of those plants from Thunberg’s herbarium – now in Uppsala – which were clearly the models of many of the drawings; some chapters on the history of Japanese botany and especially on the role played by Thunberg and by Maximowicz. Added also is an Appendix dedicated to the five fascicles published under the title of “Icones Plantarum Japonicarum”. This gives facsimiles of 50 prints, like the ‘ineditae’ accompanied by critical remarks and photographs of the corresponding herbarium specimens if any. Finally, some extensive indexes make the entrance to this work easy.