Brief history of the botanical exploration in the Gunung Leuser Natural Park and vicinity, North Sumatra With itineraries and reports of the exploration tours by Van Steenis (1937) and De Wilde & Duyfjes (1972-1991)

A concise history of the botanical collecting and abbreviated reports of the exploration tours by C.G.G.J. van Steenis and De Wilde & Duyfjes in the Gunung Leuser Park and vicinity, northern Sumatra (mainly Aceh Province) is given. This shows that essential areas of the Park, e.g. at the West side, are still botanically unknown. The remarkable achievements in field work by Van Steenis are recorded. The detailed descriptions of the itineraries give a good impression of the constitution and botanical conditions of the terrains of the interior and will be useful for the logistics of future exploration efforts in this difficult and unsurveyable area. The amount of botanical collecting done in the various vegetation types traversed is indicated. The accounts should be consulted in conjunction with the outline on the vegetation of the Park as is also presented by the authors in the Leuser Book (C. van Schaik et al., in prep.).