Spinach is my favorite leafy green vegetable. It is one tough little plant, and will keep on growing (albeit slowly) even when temperatures are very low.
A plant has a lot going on. Above ground a plant interacts with molecules in the air, absorbs light rays from the sun, battles wind, rain (or snow!) and insect pressures. Below ground plant roots twine among soil aggregates to absorb water and nutrients with the aid of mycorrhiza.