The taxon currently known as Persicaria barbata (L.) H. Hara (Polygonum L.) is widespread in warmer regions from India to China and Australia, possibly extending to the islands of the Pacific Ocean; it does not seem to occur in Africa despite reports to the contrary. There has been no ambiguity in the application of the name for at least the last 100 years. Unfortunately, the only extant material does not represent this taxon, and so new type is here proposed to conserve longestablished usage and to avoid changing the name of another well-known AsianAustralian species. (All the species mentioned here are now generally considered to belong to Persicaria but for simplicity only names in Polygonum will be used.) The only potentially relevant specimens that have been seen are in Linnaeus's herbarium at LINN, where there are two sheets identified as barbatum: No. 510.14 and No. 510.15. Neither represents the taxon traditionally known as Polygonum barbatum. Specimen No. 510.14, named barbatum in Linnaeus's script, is rather depauperate individual of P. pubescens Bl. 1825, with the gland-dotted perianth usual in that species. A later note by J. E. Smith, a China in HB, means that there was matching material from China in Banks's herbarium (C. Jarvis, pers. comm.). There is also number 79 pencilled on the lower right of the sheet, near Linnaeus's annotation. Hansen & Fox Maule (in Bot. J. Linn. Soc. 67: 189-212. 1973) believe that such numbers may indicate specimens sent to Linnaeus by Osbeck, but they are not definite on this point. Linnaeus received various Chinese specimens before 1753, mainly through Lagerstr6m from Osbeck and other travellers (Stearn in Ray Soc. Vol. 140(1): 106. 1957), so this ascription is possible. The other sheet, No. 510.15, named barbatum by Solander, is Patrick Browne collection, presumably from Jamaica and probably bought by Linnaeus in 1758 (Steam, l.c.: 108, 122. 1957). It is referable to Polygonum hydropiperoides Michx., which is known from the Caribbean region (e.g. Correll & Correll, Fl. Bahama Archip., 1982) although it is not recorded for Jamaica by Adams (Fl. P1. Jamaica, 1972). It can be discounted as material of P. barbatum, having been added to the Linnean herbarium after 1753. There are no relevant specimens known in other Linnaean collections (C. Jarvis, pers. comm.), so the only extant original specimen is herb. Linnaeus No. 510.14 (LINN), which is referable to Polygonum pubescens. In the protologue, Linnaeus cited Kraschen. comm. petr. 1747. p.375. t.13?. However, Krascheninnikov (in Novi Comment. Acad. Sci. Imp. Petrop. 1: 375-377, t. 13. 1747) was describing quite different species from China. The distinctive broadly ovate leaves, together with the comment that the species produces blue