Christ's thorn plant (Ziziphus spina-christi): flowering stem. Coloured engraving, c. 1817. https://www.rawpixel.com/image/13964154/image-flower-christs-plantFree Image from public domain licenseChrist Church, Oxford: the library. Line engraving by J. Skelton, 1817, after Archdeacon Gooch. https://www.rawpixel.com/image/13990008/image-christ-person-churchFree Image from public domain license