Forklore: More than a savage weed
You may think of the agaves, also known as magueys, as desert weeds, or somewhat savage hedge plants (with those sharp spikes along their fleshy, sword-like leaves) or possibly as the source of sisal, a rope fiber. You probably don't think of them as food.
But agave has often been eaten in the southwestern deserts. The early inhabitants of Baja California ate little else for several months of the year. The leaves were chewed as an emergency source of water, but the real food was the underground heart of the plant, which would be roasted in a pit full of hot rocks for three days. The nutritious result has been described as resembling "coarse, juicy but not very sweet yams." (Some sources report that it tends to cause stomach ache.)
Roasted agave heart is the same product that in Mexico is fermented and distilled to make mezcal and tequila. The tall, flowering stalks of the plant -- they appear only when the agave has accumulated enough food resources, which may take eight to 20 years, giving the agave its other name: century plant -- can be pit-roasted the same way.
Two other cool things about agaves: They have been grown in Hawaii because they do fine on otherwise worthless coral soil; hula skirts used to be made from agave fibers. And the plants are usually pollinated by bats, rather than insects.