A visual identification key to Orchidaceae of Korea

Abstract

Species identification is a fundamental and routine process in plant systematics, and linguistic-based dichotomous keys are widely used in the identification process. Recently, novel tools for species identification have been developed to improve the accuracy, ease to use, and accessibility related to these tasks for a broad range of users given the advances in information and communications technology. A visual identification key is such an approach, in which couplets consist of images of plants or a part of a plant instead of botanical ter-minology. We developed a visual identification key for 101 taxa of Orchidaceae in Korea and evaluated its per-formance. It uses short statements for image couplets to avoid misinterpretations by users. The key at the initial steps (couplets) uses relatively easy characters that can be determined with the naked eye. The final steps of the visual key provide images of species and information about distributions and flowering times to determine the species that best fit the available information. The number of steps required to identify a species varies, ranging from three to ten with an average of 4.5. A performance test with senior college students showed that species were accurately identified using the visual key at a rate significantly higher than when using a linguistic-based dichotomous key and a color manual. The findings presented here suggest that the proposed visual identifica-tion key is a useful tool for the teaching of biodiversity at schools, for the monitoring of ecosystems by citizens, and in other areas that require rapid, easy, and accurate identifications of species. A method that allows the accurate identification of plant species is a fundamental process in plant systematics (Simpson, 2010). Such a method provides a basic tool not only for inventory purposes and for a clear understanding of the phylogenetic relationships of plant taxa, but also for the conservation, management, and sustainable usage of plant resources. A dichotomous key is the method commonly used for species identification, and this tool is typically available in many taxonomic revisions and local floristic treatments (Ohwi, 1965; Gleason and Cronquist, 1991; Cope, 2001; Lawrence and Hawthorne, 2006; Park, 2007). Recently, new approaches have been developed to facilitate species identification using computer programs. The interactive key is one such tool, with which users initially choose any characters which are readily available and select the appropriate character state given by the key. The basic algorithm of an interactive key is to search for a taxon by eliminating taxa that do not have the selected character state. The flexibility of choosing characters at the beginning and the subsequent steps not predetermined by the key make interactive keys easily accessible to non-specialists. Several programs have been developed for various taxa, such as Intkey for DELTA System (Dalwitz et al., 1993; Coleman et al., 2010), ActKey (Brach and Song, 2005), Dryades (Nimis et al., 2012), Linnaeus NG (Doorenweerd et al., 2014), FRIDA (FRiendly Identification) (Martellos and Nimis, 2015; Martellos et al., 2016), and WEBiKEY (Attigala et al., 2016). A visual identification key is an approach which utilizes electronic keys with images of plants or a part of a plant for couplets rather than technical terminology (Kirchoff et al., 2011). A broad range of users, including non-specialists who are unfamiliar with botanical terminology, may find it helpful to use a visual identification key to identify species. With advances in information and communications technology and