Plant identification in response to poison control inquiries poses problems for medical staff and botanists alike. Lack of a specimen for verification combined with a limited description by an untrained lay person hinders confident identification of the plant. In view of these problems a computer identification system has been developed for use in answering poison control calls. A database has been compiled for 103 common houseplants described in lay terms, with respect to 56 features each possessing a number of possible states. The database is used with the MS-DOS polyclave program ONLIN6. Identifications are made by entering data for available features, so as to eliminate taxa until a single taxon remains. This system has been used in 112 mock calls in which the resulting identification could be checked. These trials resulted in correct identifications 65% of the time. Errors were attributed primarily to problems related to translation of character states into lay terminology. Revision of the database is planned that will eliminate these problems. Use of the system by hospital personnel is recommended only after graphics screens have been added to the database, and where staff have been specially trained in botanical terminology and in use of the ONLIN6 program.