Abstract
The diversity of Orchidaceae in the state of Espírito Santo, southeastern Brazil, was reassessed 40 years after the last comprehensive survey conducted for the region. The study was based on the examination of herbarium specimens, a critical review of the literature, and targeted field expeditions carried out in different phytophysiognomies. A total of 730 taxa (728 species, one subspecies, and one variety) were documented, representing an increase of 130 taxa compared to the 600 previously recorded by Augusto Ruschi. Of these, 39% are currently included in a threat category on the official Red List of Espírito Santo. Species richness is concentrated mainly in two geopolitical microregions, Central Serrana (446 taxa) and Southwest Serrana (414 taxa), which encompass important remnants of montane and submontane Atlantic Forest. The results confirm Espírito Santo as a major center of orchid diversity within the Atlantic Forest domain and emphasize the relevance of its remaining forest areas for biodiversity conservation. The substantial increase in documented species highlights the importance of continuous floristic inventories, taxonomic revisions, and updated conservation assessments to improve knowledge of regional plant diversity and to support long-term conservation planning initiatives.