This study was conducted in the Prof. Dr. Karl Arens Reserve, Corumbataí, São Paulo. The area is a Cerrado fragment, with no records of fire since 1962 and is characterised by the predominance of Cerradão phytophysiognomy. Although several studies have been conducted in the Reserve, there was no testimony material for some species in the Herbarium Rioclarense (HRCB), nor a list of vouchers for any taxon in the main publications. Thus, the objective of this work was to undertake a floristic survey of the woody species in the Reserve, based on herbarium specimens and fieldwork.<br> The survey in HRCB recorded 510 exsiccatae belonging to 160 species and 44 families. We also conducted 24 fieldwork expeditions between 2019 and 2021 and recorded 118 species in 39 families. In total, 193 woody species were recorded for the Reserve in Corumbataí. Species such as Copaifera langsdorffii and Myrcia neoclusiifolia had already been cited for the area, but there was no testimony material in the herbarium. Machaerium nyctitans and Alchornea glandulosa are examples of new records for the Reserve. Fabaceae, Asteraceae, Myrtaceae, Melastomataceae and Rubiaceae were the families with the greatest species diversity.
