Also called flowering (white) cabbage and Chinese flowering cabbage, this vegetable is, as one might guess, a member of the cabbage family. It has pale green stems and rounded, medium-green leaves. The leaves have a sweet, delicate flavor, and the crunchy stems have a pleasant bitter nuance. Sometimes the inner stems are tipped with tiny yellow flowers. Choy sum (Chinese for "flowering green") is available in Asian markets and some specialty produce markets. It should be refrigerated in a plastic bag for no more than 4 days. It can be used raw in salads or cooked in a stir-fry or as a vegetable. See also yu choy sum.
From The Food Lover's Companion, Fourth edition by Sharon Tyler Herbst and Ron Herbst. Copyright © 2007, 2001, 1995, 1990 by Barron's Educational Series, Inc.