Manna is a commonly used traditional Chinese medicine, belonging to the perennial herb family Lamiaceae. When people eat it, they mainly eat a screw-shaped fat stem on its rhizome. The shape of this part is very similar to that of silkworms, and they are also called ground silkworms and grass caddis silkworms. The scientific name of manna is Manluzi, also known as grass caddis, Diliuzi, spiral cabbage, pagoda cabbage, screw cabbage, etc.

Form: There are stolons underground, and the top expands into a spiral fleshy tuber when mature. Stem erect, 30-120 cm tall, square. The leaves are opposite, ovate to oblong-ovate, with short bristles attached to both sides.

Blooms in summer, with lip-shaped flowers, light purple, in umbels; the corolla is about 1.2 cm long, with hair rings inside the tube, the upper lip is upright, the lower lip is three-lobed, and the middle lobe is nearly round. Nutlets are oval, with small tubercles. It likes growing in warm and humid lands or near water.

It is found wild or cultivated in various parts of my country, and is rare in western Beijing. Most of them are in Hebei and other places bordering west Beijing. Instructions for consumption: Wash the manna seeds and boil them in water. After boiling for a period of time, drink the boiled water. The pickled manna is white and yellow in color, salty and fresh in taste, and has a rich sauce flavor.