Generally wild watercress will have parasites; while those grown in soilless planting and using nutrient solution directly generally do not contain parasites and will also be more tender. Watercress that contains parasites needs to be fully washed, salted, blanched and other sterilizing and de-worming cleaning before consumption.

Watercress generally refers to watercress. Watercress is an umbelliferae, perennial herbaceous plants, stems erect or basally creeping. Basal leaves are stalked, with leaf sheaths at the base; leaf blades are triangular in outline. Compound umbels terminal; without involucre; rays unequal, erect and spreading; calyx teeth linear-lanceolate, petals white, obovate, with a long and inflexed ligule; stylopodium conic, erect or branched on both sides. Fruit subquadrangular-ellipsoid or cylindrical-oblong, lateral ribs more elevated than dorsal and middle ribs, corky. Flowering June-July, fruiting August-September.