1911 Encyclopædia Britannica/Celery
CELERY (Apium graveolens), a biennial plant belonging to the natural order Umbelliferae, which, in its wild state, occurs in England by the sides of ditches and in marshy places, especially near the sea, producing a furrowed stalk and compound leaves with wedge-shaped leaflets, the whole plant having a coarse, rank taste and a peculiar smell. It is also widely distributed in the north temperate region of the Old World. By cultivation and blanching the stalks lose their acrid qualities and assume the mild sweetish aromatic taste peculiar to celery as a salad plant. The plants are raised from seed, sown either in a hot bed or in the open garden, according to the season of the year, and after one or two thinnings out and transplantings, they are, on attaining a height of 6 or 8 in., planted out in deep trenches for convenience of blanching, which is effected by earthing up and so excluding the stems from the influence of light. A large number of varieties are cultivated by gardeners, which are ranged under two classes, white and red,—the white varieties being generally the best flavoured and most crisp and tender. As a salad plant, celery, especially if at all “stringy,” is difficult of digestion. Both blanched and green it is stewed and used in soups, the seeds also being used as a flavouring ingredient. In the south of Europe celery is seldom blanched, but is much used in its natural condition.
Celeriac, or turnip-rooted celery (Apium graveolens var. rapaceum), is a variety cultivated more on account of its roots than for the stalks, although both are edible and are used for salads and in soups. It is chiefly grown in the north of Europe. As the tops are not required, trenching is unnecessary, otherwise the cultivation is the same as for celery.