Holy thistle (Centaurea benedicta) illustration. Digitally enhanced from our own book, Medical Botany (1836) by John… https://www.rawpixel.com/image/327162/free-illustration-image-thistle-flower-centaurea-benedictaFree Image from public domain licensePng yellow thistle flowers vintage sketch https://www.rawpixel.com/image/2611552/free-illustration-png-herbal-medical-botany-holy-thistleView licenseA blessed thistle (Cnicus palustris) with an associated insect and its anatomical segments. Coloured etching, c. 1830. https://www.rawpixel.com/image/13981746/image-paper-butterfly-flowerFree Image from public domain licenseHoly thistle (Centaurea benedicta) illustration from Medical Botany (1836) by John Stephenson and James Morss Churchill. https://www.rawpixel.com/image/327161/premium-illustration-psd-holy-thistle-centaurea-antiqueView license