J. M. Despréaux' lichens from the Canary Islands and West Africa: An account of a 19th century collection found in an English archive

Abstract

This is an historical and descriptive account of 28 herbarium specimens, 27 lichens and an alga, found in the archives of Charles Chalcraft, a descendant of the Bedford family, who were dye manufacturers in Leeds, England, in the 19th century. The lichens comprise 13 different morphotypes collected in the Canary Islands and West Africa by the French botanist J. M. Despréaux between 1833 and 1839. The collections include samples of Roccella fuciformis, R. phycopsis and R. tinctoria (including the fertile morphotype R. canariensis), Ramalina crispatula and R. cupularis, two distinct morphotypes of Sticta, S. canariensis and S. dufouri, Physconia enteroxantha, Pseudevernia furfuracea var. ceratea and Pseudocyphellaria argyracea. The herbarium also includes authentic material of Parmotrema tinctorum and a probable syntype of Seirophora scorigena. Most of these species are known as a source of the purple dye orchil, which was used to dye silk and wool. © 2011 The Linnean Society of London.