Studies of Equiseta in European Herbaria

Abstract

Various problems in relation to certain species of Equisetum had presented themselves to the writer which he was not able to solve with the inadequate material in American herbaria. The summer of 1930 was, therefore, spent in Europe in studying herbarium material and the opportunity was also afforded of attending the Fifth International Botanical Congress at Cambridge, England, August 16-23. The investigations were made at the following herbaria where a large number of records on the geographic distribution of all the species was also obtained: The Amsterdam Botanic Garden, the Berlin Botanic Garden, the Basel Botanic Garden, the Zurich Botanic Garden, the Herbier Boissier of the University of Geneva, the Herbier Delessert of the Geneva Botanic Garden, the Herbarium of Cambridge University, the herbarium of the British Museum of Natural History, London, the Linnean Herbarium owned by the