Stachys affinis (Syn.: Stachys sieboldii), commonly called crosne, Chinese artichoke, Japanese artichoke, knotroot, and artichoke betony, is a perennial herbaceous plant of the family Lamiaceae, originating from China. Its rhizome is a root vegetable and can be eaten raw, pickled, dried or cooked. 
Stachys affinis is a perennial herbaceous plant with red to purple flowers and reaches a height of 30 – 120 cm. The green leaves are opposite arranged on the stem. The rough, nettle-like leaves can be ovate-cordate shaped with a width of 2.5 – 9.5 cm or ovate-oblong with a width of 1.5 – 3.5 cm. The leaves are separated in leaf blade and a petiole. The petiole has a length of 1 – 2 cm and becomes shorter towards the stem apex. Similar to the potato, Stachys affinis grows storage roots which are approximately 8 cm long and 2 cm thick. They are formed by thickening rhizomes at the root ends. By medullary[disambiguation needed] primary growth they thicken primarily on the internodes and less on the nodes. This way at irregular intervals constricted tubers are formed, which are usually thinner on both ends. The tubers are surrounded by a thin pale beige to ivory-white skin. The flesh underneath is white and tender.
Stachys affinis originates from central and northern China.  Before Stachys affinis has been domesticated, a related crop named Stachys palustris was collected in nature to consume as a legume in the time before christ. Later on the Germanic peoples used Stachys recta, which is a further relative of Stachys affinis as medicinal plant. Stachys affinis was then cultivated from the 18th century on. 1882 the crop was cultivated on a farm for the first time in Crosnes.  Stachys affinis is the only labiate which is cultivated as vegetable in Europe. At the beginning of the 20th century Stachys affinis became more and more popular until it was abandoned again in the 70’s due to problems with viruses and the plants strong vagility.  Since 1990 there has been a rise in the cultivation of Stachys affinis again and it is available on markets and in some grocery shops. Today the plant is listed in the “Handbook of Alien Species in Europe” as invasive plant for Europe. 
The plant is part of the family Lamiaceae. Before the plant was officially named Stachys affinis it was called Stachys sieboldii. This name was dedicated to the German-Dutch botanist and researcher on Japan Philipp Franz von Siebold.
Stachys affinis is planted as a bulb (vegetative) in spring (March - Mai). Multiple bulbs are planted 5 to 8 cm deep into one hole of soil spaced 30 by 30 cm. The plant is achieving a hight of 30 cm. Weeding is necessary but it is important not to damage the root system. A sufficient water supply during summer is important.
Harvest is in fall and winter (November – March). It is important that the soil is not frozen while harvesting.
The storage of Stachys affinis tubers is difficult. Because of there thin skin, they are just a few days storable. They can be stored about one week in the fridge. An alternative can be a fresh ongoing harvesting out of humid sand, there by the tubers stay fresh for several months.
The tubers have a crunchy texture and a sweet, nutty flavour. They can be eaten raw, pickled, dried or cooked. A wide range of uses for this vegetable leads to various dishes in many countries’ kitchen. They can be prepared similarly to Jerusalem artichokes.
In Chinese and Japanese cuisine, the Chinese artichoke is primarily pickled. In particular, its tuber is a part of Osechi, cooked for celebrating Japanese New Year. Dyed red by leaves of red shiso after being pickled, it is called chorogi. In Korea it is called ChoSeokjam.
In French cuisine, its cooked tuber is often served alongside dishes named japonaise or Japanese-styled.
Additionally it can be said, that root extract of Stachys affinis showed antimicrobial activity. Further Baek et al. observe antioxidant activity in 2004. Also in 2004 inhibitory effects on acetylcholine esterase, monoamine oxidase and xanthine oxidase activities were observed in rat brains after 20 days feeding with methanolic extracts of Stachys affinis. Ethanol extract from this plant also seems to have antitumour activity.
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