Paris Island Cos Organic Lettuce Seeds Heirloom Vegetable. Romaine type lettuce growing to about 25 cm (10″) in height with loosely packed emerald green leaves sheltering on inviting creamy white heart. Leaves are crisp and fresh tasting even in simmer warmth. Good resistance to bolting with decent tolerance to tip burn. This variety has been grown since at least the early 1800's.