Abstract
Since the publication of the last Lebanese and Syrian classical flora, the only complete work on Lebanese flora is an illustrated book based on the same taxonomy and nomenclature with a few exceptions and some additions. Specifically on the Lebanese orchids, one book has illustrated orchids in the field with an unusual taxonomic point of view. Several Euro-Mediterranean monographs propose a conflicting taxonomy that is not always useful in identifying living specimens. Several years of exploration throughout Lebanon allowed the authors to build considerable knowledge of the orchid flora and its taxonomy. Other works made on adjacent areas completed the investigations and provided some useful indications to build taxonomic understanding and compile a preliminary checklist of Orchidaceae. Historical nomenclature was reanalysed from a modern point of view; recent critical appellations were confronted with biogeography and integrative evolutionary taxonomy, and some poorly known taxa are highlighted and their taxonomy is reinvestigated. A total of 51 species and subspecies are listed for Lebanon. Two new chorological records for Lebanon (Epipactis helleborine ?subsp. praecox? nom. provis.; Ophrys alasiatica) and four new nomenclatural combinations (Androrchis ? ehdenica, Epipactis helleborine subsp. turcica, Ophrys episcopalis subsp. libanotica, Serapias vomeracea subsp. levantina) are presented. At least 14 taxa are regionally endemic, seven of which are limited to two border countries, the other seven being too poorly known for conclusions about their biogeography