The Meiwa kumquat (Fortunella crassifolia) is a small, cold-hardy, evergreen citrus tree, popular for producing sweet, round fruit (about 1-inch diameter) with edible skin. Ideal for in-ground (8-11 ft) or container (6-8 ft) growth in zones 8-11, this self-fertile, slow-growing tree is often preferred for snacking over the tart Nagami variety.