Since the foundation of the Rijksherbarium, pteridophytes have been an important part of the total collections. Blume, the first director, had a special interest in ferns. In 1826, when he returned to Europe from his stay in Java, he took with him large collections of well preserved pteridophytes which he had gathered there himself. These, together with the fern collections of Van Hasselt, Kuhl (both from Java), and Zippel (Java, Moluccas, New Guinea), were all deposited in the Rijksherbarium. Blume’s studies on the ferns of Java, both in the wild and in the herbarium, were published before the foundation of the Rijksherbarium in the second fascicle of the ‘Enumeratio Plantarum Javae et insularum adjacentium minus cognitarum vel novarum’ (1828) in which the author enumerated 500 species of ferns and fern allies of which, apart from many new varieties 338 were new to science. Moreover, five new genera were proposed: Kaulfussia (a synonym of Christensenia), Gymnosphaera, Diacalpe, Arachniodes, and Stegnogramme. Although no keys are provided, the concise descriptions are diagnostic and meet the highest scientific standards. For nearly all the taxa, additional information on the habitat or the precise locality is given. No words can better illustrate the high quality of Blume’s work then by stating that most of the species at present recognized as being native to Java, are included in the ‘Enumeratio’. It was indeed the first critical fern flora for a tropical region, convincingly displaying the enormous diversity to be found in circumstances of a warm climate and high humidity. The ‘Enumeratio’ was followed by the Flora Javae(1828— 1851) in which Blume illustrated over a hundred fern species — nearly"""" all of them for the first time — on 96 hand coloured folio plates of which the typography, especially of the first fascicles, is superior.