define "weed"

i was watching "king corn” ( again ) last night and there is a scene in the “june” chapter in which the topic is spraying herbicide ( atrazine ) to control weeds…ignoring the health issues involved in runoff of agricultural chemicals, the farmer earnestly begins listing the “weeds” that were the nemesis of his yield and the first “weed” on his list was lamb’s quarters…there are lamb’s quarters in my backyard and in the iu northwest community garden and just about anywhere you find Jerusalem artichokes ( like the ones in my backyard )…they are native and they are edible…both seeds and leaves…the leaves can be used as you would spinach or as greens in a salad…they’re only a “weed” on his farm because they aren’t a cash crop…in “defense of food” michael pollan says: “a century ago the typical iowa farm raised more than a dozen different plant and animal species: cattle, chickens, corn, hogs, apples, hay, oats, potatoes, cherries, wheat, plums, grapes, and pears. now it raises only two, corn and soybeans.” the use of chemical inputs has simplified the make-up of the soil ( and reduced the quantity of nutrients available to the plants, and so, to we who eat them…have a look at sir albert howard’s “ soil and health”…the whole issue goes farther back than pollan’s popularization ) and the monoculture of corn and soybeans has reduced the dietary choices we have…supermarkets crammed full of processed “value added” foods are trying to obviate the need for whole foods…a hostess apple pie or a honeycrisp? Lays potato chips or a simple spud from the garden? there's a lot more out there in terms of food than kraft or nestle or monsanto are prepared to admit...all you have to do is a bit of research and find some empty ground to do some gardening to get , at least in part, past the system...grow some stuff to eat that the food establishment doesn't recognize as "food" and the ponder on how you feel about what you've accomplished... this is why the header on this blog says “diversity in place of monoculture” and why i’m a fan of milpas and buffalo bird woman…i have a stove again…time to dig some tubers.