1. Potatoes or manna seeds, formerly known as grass silkworms, are also called "earth circles". It is a perennial plant of Labiatae. The underground rhizome is spiral, crisp and fiber-free, and can be used to make kimchi. This product is native to China, distributed all over the country, and cultivated in low-lying wetlands near water. Stems, leaves and roots can all be used as medicine.

2. Morphological characteristics: POTAMOGETON POTAMOGETON is a perennial herb, with a height of 30- 1.20 cm, dense fibrous roots and the most transverse rhizomes at several nodes at the base of the stem; The rhizome is white, with scales and fibrous roots at the nodes, and a beaded or snail-like hypertrophy tuber at the top. Stems erect or base inclined, simple, or multi-branched, quadrangular, grooved, with spreading or sparse or dense bristles on edges and nodes. Cauline leaves are ovoid or oblong, 3-12cm long and1.5-6cm wide. The top is slightly pointed or tapered, the base is flat to shallow heart-shaped, sometimes it is wide wedge-shaped or nearly round, and the edge has regular crenate serrations. The inner surface is covered with bristles, but only along the veins, with 4-5 pairs of lateral veins. Bract leaves gradually change, slightly upward, bract-like, usually reflexed (especially cultivated). The lower part is sessile, ovate-lanceolate, about 3 cm long, longer than the whorl, tapering at the top, nearly round at the base, short at the upper part, sessile, lanceolate, shorter than the calyx, nearly entire. Cymes usually have 6 flowers, most of which are far from the terminal spike and 5-15 cm long; Bracteoles linear, about 65438 0 mm long, puberulent; Pedicel short, about 65438 0 mm long, puberulent.