 Plants like onion ("Allium cepa"), hyacinth ("Hyacinth"), narcissus ("Narcissus") and tulips ("Tulipa") reproduce by dividing their underground bulbs into more bulbs.Other plants like potatoes ("Solanum tuberosum") and dahlia ("Dahlia") reproduce by a similar method involving underground tubers.Gladioli and crocuses ("Crocus") reproduce in a similar way with corms.