An anthotype or phytotype is a print made using plant matter. To make one, you crush some part of a plant enough to get the juice out of it, coat paper with the juice, and put the paper out in the sun with something over it to block the light (a positive transparency or object). Once it’s out in the sun, forget about it for a few days to a few months. Over time, the sunlight changes the color and/or intensity of the plant juice, more where it strikes, less where it is blocked, leaving an image. Every plant gives a different result, leaves will give a different result than berries, berries will give a different result than flowers. Different papers or times of year will change the final image, even which side of the yard the plant grew up on. 
Making a phytotype is a whole and slow experience, something akin to growing a century plant to make a cup of tea. It stains your fingers and frees intense fragrances. There is very little certainty, it is mostly guessing and learning to love the results. Retakes use up months. The final print, with its weight of time and soul investment, can’t really be called final as the plant juice will continue to change and fade after you take it out of the sun. Depending on what plant and paper was used and how it is stored, the print may be utterly gone in less than a year, or it may still be readable two hundred years from now. Phytotypes are a little Puckish.
If you are going to make a phyototype, there is a lot more concrete information here. (Most practitioners call them anthotypes; I prefer phytotypes because ‘antho’ refers only to flowers and I’ve never yet made one using flowers. “Phyto’ refers to all plants. I like to be precise when I’m being imprecise.) I use plants that I grow here in my garden and throw a little vodka into the juice to increase the contrast of the print. Mulberries and elderberries have treated me well. So have cabbage leaves and silverbeet. When choosing an image, try to find one that doesn’t depend on subtle tones, preferably one that communicates better in some deep, unutterable way from being made out of spinach or cornflower or wine. Easy.
If I am successful in printing, then I have caught the plant in the arc of its dying and joined it to my own life, which is a part of my own dying. That is what photography does when it is working. The print will emerge pale pink or blue or electric green, and it will change every day until over days or over years it will be illegible and then it will be gone. Like the day summers ago my son had no front teeth and my husband shook so many mulberries out of the draping tree we decided to make mulberry pies and then, full of pie, mulberry prints. It lives for now, written on my squishy innards, changing every day until it will be illegible and then it will be gone.