Gentian (Gentiana holopetala) (1936) by Mary Vaux Walcott. Original from The Smithsonian. Digitally enhanced by rawpixel.
https://www.rawpixel.com/image/2613496/free-illustration-image-flower-wildflowers-hand-drawn-vintage-purple-watercolorFree Image from public domain license
Hand drawn willow gentian. Original from Biodiversity Heritage Library. Digitally enhanced by rawpixel.
Bitter root (Gentiana lutea) illustration. Digitally enhanced from our own book, Medical Botany (1836) by John Stephenson…
https://www.rawpixel.com/image/327107/free-illustration-image-bitter-root-flowers-public-domain-yellow-flower-watercolorFree Image from public domain license