PORRUM, the LEEK; a species of plants, belonging to the genus of ALLIUM. There are two species known in this country; the fativum, or London leek, and the ampeloprasum. The first is the kind commonly cultivated; and of it there have been supposed two varieties: but Mr Miller observes, that the difference has been occasioned by some persons saving the seeds from old leeks, and not from the seedling leeks; whereby they have degenerated, and become smaller and narrower-leaved; but may be recovered again by proper care. The other species is a native of Siberia; its leaves are narrower than the common sort; the stalks are smaller, and do not rise near so high; the heads of the flowers are also smaller, and of a purplish colour; the lamina stand out beyond the flower. Leeks are cultivated in the same manner as onions, and commonly sown along with them; their qualities as food are also the same.