I have decided to use this photograph I took of a Sida cordifolia leaf for the final design of the book cover for Edn™:
A Sida cordifolia leaf
As the alien plants in the novel have a purple phosphorescent hue to them, I have again inverted the image in Photoshop. I particularly like straggly plant fluff clinging to the stem in the photograph, as it illustrates the extra-terrestrial spore and regenerative power of the plants very nicely indeed. I hope.