The first North American records of this East Asian genus were from southeastern Ky. in the 1940s (Rogers 1942; F). Mosla was not collected by B during her extensive field work of the 1930s. The species was initialy identified by McFarland, Rogers and Deam (11 Oct 1941 at GH) as M. lanceolata (Benth.) Maxim., which is now considered a synonym of scabra (Flora of China 17). However, apparently due to Fernald, the North American plants became generally known as the closely related M. dianthera (Buch.-Ham. ex Roxb.) Maxim. M. scabra has now become locally frequent in several hilly regions of eastern states, especially on or near the Cumberland Plateau in Ky., Tenn. and nw. Ga. (K, SE). There is a more recent cluster of records centered in eastern Va. (W). M. scabra mostly occurs along trails in dry woods on acid soils. The plant has traditional culinary and medicinal uses in East Asia, with chemistry somewhat similar to the closely allied genus, Perilla. Whether true dianthera occurs in Ky. or elsewhere in North America remains uncertain. M. scabra differs from dianthera as follows (W): leaves narrowly ovate (versus ovate to widely ovate), margins with 5-10 pairs of shallow teeth (versus 4-7 deep teeth); upper lip of calyx deeply (versus shallowly) toothed, teeth narrowly (versus broadly) triangular; nutlets densely (versus loosely) netted. Both species are widespread in East Asia, but scabra is concentrated in warmer regions, on drier sites, and at lower elevations: 0-1100 m versus 200-2300 m in China (Flora of China 17; M. Brock, pers. comm.). Hybridization has been reported from Taiwan (Hsieh & Huang 1999). Further study of North American material is needed.