Apium graveolens variety rapaceum. Umbelliferae. A biennial usually grown for its celery-flavoured root. The foliage is like that of celery but it is distinguished by its globe-shaped, rather rough, knobbly root. Roots are ready to lift from autumn into early winter. They can be stored throughout winter, either in situ where they will tolerate ambient temperatures to –12ºC, or in boxes of sand in a cool dry shed. Cultivation is similar to that of self-blanching celery. Any side-shoots developing in the late summer when the roots begin to swell should be removed to encourage the formation of large individual roots. Celeriac can be shredded or cubed to be eaten in salad, or served boiled. The leaves may also be used fresh to flavour soups and stews. Cultivars are not very distinctive but ‘Claudia’ is recommended for its smooth non-branching roots. ‘Balder’ produces round, medium-sized roots. Some seedsmen divide cultivars into short-leaved (e.g. ‘Alabaster’, ‘Glabus’, ‘Marble Ball’ and Tellus’) and long-leaved (e.g. ‘Monarch’). Pests and diseases are similar to those of celery. Carrott fly larvae will sometimes tunnel into the roots.