A novel actinobacterium, designated RS-15T, was isolated from rhizosphere soil of a plant (Peucedanum japonicum Thunb.) on Mara Island, Jeju, Republic of Korea. Cells were strictly aerobic, Gram-stain-positive, oxidase-negative, catalase-positive, non-motile, irregular, short rods. The peptidoglycan in the cell wall was of the B2beta type with ornithine as the diagnostic diamino acid. The major menaquinone was MK-8; small amounts of MK-9 and MK-7 were also present. The polar lipids contained phosphatidylglycerol, five unknown glycolipids, three unknown phospholipids and two unknown lipids. Mycolic acids were not present. The predominant fatty acids were summed feature 7 (one or more of C18:1omega9c, C18:1omega12t and C18:1omega7c), anteiso-C15:0 and C14:0 2-OH. The DNA G+C content was 68.3 mol%. 16S rRNA gene sequence analysis showed that strain RS-15T belonged to the family Microbacteriaceae and formed a tight phylogenetic cluster with Frondihabitans australicus E1HC-02T (98.5% sequence similarity). The DNA-DNA relatedness between strain RS-15T and Frondihabitans australicus DSM 17894T was 17.2% (17.1%, duplicate measurements). On the basis of the physiological, chemotaxonomic and DNA-DNA hybridization data, strain RS-15T is considered to represent a novel species of the genus Frondihabitans, for which the name Frondihabitans peucedani sp. nov. is proposed. The type strain is RS-15T (=KCTC 13435T =DSM 22180T). An emended description of the genus Frondihabitans is also presented.