Manually-constructed keys to many groups of the Egyptian flora are in urgent need of improvement and updating. To construct a conventional substitute of the key to representatives of the Lamiaceae, a data matrix was compiled to include 48 characters recorded for each of the 52 species (with three subspecies and one
variety) belonging to 24 genera which represent this family in the flora of Egypt. The 48 characters were accurately defined to cover as much of the easily observable aspects of vegetative and floral variation in the plants as possible. The data matrix was analyzed using the key-generating package of programs DELTA. The analysis produced a conventional key with a detailed description of every species in terms of the 48 characters. The key is decidedly a marked improvement over its predecessors in that it is strictly comparative. Updating the nomenclature of the plants led to the first recording of the genus Thymbra in the flora of Egypt.