by Edgar Anderson
A portion of an essay from: Bulletin of the Missouri Botanical Garden, vol. 43, pp. 50-53, 1955
If you're an adult and you want to teach yourself how to find out about plants there is no more convenient way to start. Get a potato, a nice big one, out of the bin, wash it off carefully, and sit down in a comfortable chair with a good light coming over your shoulder. Turn the potato over in your hands. Don't be too terse and earnest. If you can get a friend with kindred interests to join you, so much the better and if you talk about other things now and then it's all to the good. Just try to build up a little intelligent enthusiasm for this starchy sphere which previously you have taken so for granted.
Well, let's look at the potato. Most obviously it has eyes. Nearly everybody knows this much, yet have you really ever looked a potato in the eye? There is something more or less like an arching eyebrow with an eye-hollow within the arch and coming up out of this hollow are little dark buds. Now notice the arching eyebrows. They don't arch any old which way; they are all focused in the same direction. To our surprise we will learn that each potato has a well-defined front end an equally well-defined rear end and that these are very different in appearance. At the front end the eyes are clustered closely together, the buds always frontwards from the arching brow. This brow is really a kind of leaf, or the mark where such a scale leaf was borne and then fell off. Sometimes new potatoes will show delicate little membrane-like scales rising up off the tuber's surface in these arching lines; in the ordinary grocery-store spud the membranaceous scale has usually gone by and only a faintly curving scar is left. Now turn the potato about and look at the other end, then examine the whole region in between. At the other extreme from the active apex with its closely clustered buds you will find either a piece of the little round underground stem on which the potato was formed or the neat little circular scar where this stem was broken off.
A potato, you see, is what botanists call a tuber. It is just the swollen coalesced buds at the end of an underground stem. It is not a root; it is part of a true stem though borne underground. Like all stems, it has joints (the technical word is nodes) at which leaves (or leaf-like scales) are borne and it is in the axils of these scales that all the new branch stems arise when the potato is sprouted. This is how one tells stems from roots in those plants with both underground stems and true roots. Stems have nodes (joints); roots don't. Stems have leaves or scales at the nodes; roots have neither. If you find a root with some little scales on it at fairly regular intervals, it isn't a root. It's an underground stem of some sort. Finally, stems are precise in their pattern of growing; they branch only in the axils of the leaves or scales; roots branch only irregularly.
Our humble potato is therefore a much more precisely organized bit of life than one would have imagined. Like virtually all life it is highly polarized. It has a head end, an apex, at which growth is most active. It has an innate orientation to up and down, to frontwards and backwards. Plant your potato in a bowl of sand or sawdust or vermiculite, keep it well watered and watch its development for a few weeks. See the way the new stems sprout out from the buds near the apex. Plant another potato in the garden and dig it up and wash off the roots after the plant is well developed. You will be able to see for yourself the difference between the true roots and the jointed underground stem on which the potatoes are borne.
So what? Well, you'll have made a beginning at understanding for yourself the world around you. The world looks chaotic; deeper study shows us the order in it; with still deeper and more intensive study we are able to understand enough of the order underneath the apparent chaos so as to work with it rather than against it.
So if plants are beginning to interest you and you wish you knew more about them, no need to sigh for lost opportunities, no need for that magic book which will tell you painlessly the very things you wish you knew. Sit down quietly with a potato, a nice large, clean potato. Relax in your chair. Take a friendly interest in this succulent brown blob which you have previously ignored. Let it become a simple introduction to learning about plants from plants themselves. Take your first step towards botanical insight by spending a nice quiet evening with a potato.