This plant is in the Eat-the-Weeds category. Available for free on a roadside near you.
Amaranth is a common roadside weed wherever sunshine and water meet soil. Commonly harvesting when young, to be eaten like spinach, it grows fibrous and weedy very quickly. The mature plant, one to two meters high, carries a characteristic plume at the very top, consisting of a dense wand of sharp spikes, holding a multitude of roundish, black, shiny seeds that easily shake out.
For greens to cook, nip off the tops from young plants. The younger the better. Growing tips may be picked until seed head starts forming, making the bud fibrous and inedible. The seeds can also be harvested by carefully pulling a bag over the seed head, then snapping it off, causing the multitude of tiny seeds to drop into the bag. Empty bag into container and repeat at will. A good bush can have six or eight large seed heads.
The greens are cooked the same way as spinach, prepared the same way as spinach, flavoured and otherwise with ingredients same as spinach.
The seeds are a favourite for some birds, almost all chicks, and are high in protein to add to other feed mixes. The seeds can also be popped like popcorn, and makes for a rather satisfying snack.
This is a food plant with no other known uses. Attempts are being made to commercialise the plant, with hybrids and interbreeds being experimentally farmed in America. Disregarding the problems associated with hybrid food seed; the amaranth does not really tolerate monoculture, and succumbs to all sorts of diseases and parasites not normally associated with ubiquitous weeds.