Barley, Brown rice, Buckwheat, Millet, Oatmeal, Rye, Wheat germ, Wheat, hard red, Wild rice, Apples, Bananas, Cantaloupe, Grape, Grapefruit, Honeydew melon, Orange, Papaya, Peach, Pear, Pineapple, Strawberry, Tangerine, Watermelon, Artichokes, Beets, Broccoli, Brussels sprouts, Cabbage, Cauliflower, Cucumbers, Eggplant, Green peas, Green pepper, Kale, Lettuce, Mushrooms, Mustard green, Onions, Potatoes, Spinach, Tomatoes, Turnip greens, Watercress
These are all sources of protein and as long as vegetarians (and everyone else, for that matter) eat a wide variety of foods, they will easily manage to eat enough protein