Horseradish root, very tenacious of life, is a perennial, thick, tapering, white, long, acrid, and from which arise many large leaves. From the center a round or angular, smooth, erect, branching stem arises, about 2 feet in height; those branches which flower are corymbose, smooth, and angular. The radical leaves are nearly a foot long, half as wide, oblong, crenately-toothed, waved, sometimes pinnatifid, of a dark-green color, and upon long, channeled petioles; the cauline leaves are smaller, lanceolate, dentate, or incised, sessile, sometimes entire, and without footstalks; the lower ones are often pinnatifid. The flowers are numerous, small, white, peduncled, and borne in terminal corymbose racemes. Calyx ovate, spreading, and equal at the base; sepals four, concave. Petals obovate, obtuse, entire, claw-like. Stamens without teeth, the length of the calyx; anthers cordate; silicle sessile, oblong, or ovoid-globose, and compressed; dissepiment thin; valves ventricose, thickish; cells many seeded; seeds not bordered, and cotyledons flat and accumbent.

Stimulant, rubefacient (plant); antiseptic, aperient, digestive, diuretic, expectorant, rubefacient and stimulant (roots)

Horseradish
Plants for a Future
King's American Dispensatory

Allyl-isothiocyanate, arginine, gentisic acid, niacin, p-hydroxy-benzoic acid, riboflavin, sinigrin, thiamin, vanillic acid (root); ascorbic acid (plant, root); kaempferol, quercetin (leaf); limonene, raphanin, sinapic acid, tannin (plant)

In the treatment of colds, fevers and flu and is of value in the treatment of respiratory and urinary tract infections; to treat pleurisy, arthritis and infected wounds (root)