Let me recommend bok choy, a member of the crucifer family that is sometimes called Chinese cabbage. It is an excellent source of vitamins A, C and B-complex, and among garden vegetables, it is one of the highest in calcium. The crunchy, wide white or greenish-white stalks do indeed resemble unribbed celery, and they taste like a peppery or spicy celery. The green leaves are mild-tasting, similar to Swiss chard or romaine lettuce. Mature, regular bok choy is between 8 to 12 inches long.
Many Asian markets have baby bok choy, a tender and special treat.
They are only about 6 inches long and have a sweeter, nuttier flavor. You should be able to find bok choy year-round at the supermarket. Look for bunches with firm, unblemished white stalks topped with fresh-looking, crisp leaves. Avoid bok choy with brown spots or yellow patches on the leaves. The smallest bunches will be most tender and delicate.