Agriculture probably required a far greater discipline than did any form of food collecting. Seeds had to be planted at certain seasons, some protection had to be given to the growing plants and animals, harvests had to be reaped, stored and divided. Thus, we might argue that it was neither leisure time nor a sedentary existence but the more rigorous demands associated with an agricultural way of life that led to great cultural changes.
The word 'vegetable' has no precise botanical meaning in reference to food plants, and we find that almost all parts of plants have been employed as vegetables - roots (carrot and beet), stems (Irish potato and asparagus), leaves (spinach and lettuce), leaf stalk (celery and Swiss chard), bracts (globe artichoke), flower stalks and buds (broccoli and cauliflower), fruits (tomato and squash), seeds (beans), and even the petals (Yucca and pumpkin).
