https://creativecommons.org/publicdomain/zero/1.0/https://www.rawpixel.com/image/13969270Edit ImageSaveSaveEditCropCustom TextTwo species of knotweed (Polygonum species): flowering stems. Coloured lithograph by W. G. Smith, c. 1863, after himself.Original public domain image from Wellcome CollectionMorePublic DomainFree CC0 image for Personal and Business useInfoView CC0 LicenseJPEGSmall JPEG 770 x 1200 px | 300 dpiLarge JPEG 1390 x 2166 px | 300 dpiFree DownloadTwo species of knotweed (Polygonum species): flowering stems. Coloured lithograph by W. G. Smith, c. 1863, after himself.More