Hand drawn sketch of walnuts https://www.rawpixel.com/image/410128/free-illustration-image-walnut-dried-sketch-drawingView licenseCalabash and Fruits by Michiel van Huysum (1714-1760). Original from The Rijksmuseum. Digitally enhanced by rawpixel. https://www.rawpixel.com/image/513741/free-illustration-image-gourd-walnut-flower-paintingFree Image from public domain license