Stachys affinis

Stachys affinis, commonly called crosne, Chinese artichoke, Japanese artichoke, knotroot, or artichoke betony, is a perennial herbaceous plant of the family Lamiaceae, originating from China. Its rhizome is a root vegetable that can be eaten raw, pickled, dried or cooked.

Description

S. affinis is a perennial herbaceous plant with red to purple flowers and reaches a height of Template:Convert.<ref name=":0">T.K. Lim, Edible Medicinal and Non-Medicinal Plants: Volume 11, Modifi ed Stems, Roots, Bulbs, DOI 10.1007/978-3-319-26062-4_3</ref> The green leaves are opposite arranged on the stem. The rough, nettle-like leaves can be ovate-cordate shaped with a width of Template:Convert or ovate-oblong with a width of Template:Convert. The leaves are separated into a leaf blade and a petiole. The petiole has a length of Template:Convert and becomes shorter towards the stem apex.<ref name=":0" /> Similar to the potato, S. affinis grows rhizomes which are approximately Template:Convert long and Template:Convert thick. By medullary 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 covered with a thin, pale-beige-to-ivory skin. The flesh underneath is white and tender.<ref name=":0" />

Compounds

Vacuoles in the tuber of S. affinis are rich in stachyose.<ref>Template:Cite journal</ref> Stachyose is a tetrasaccharide, consist out of galactose, glucose and fructose. Stachyose is evaluated to be about 230 mg/kg in dry tubers.<ref>Template:Cite journal</ref>

Origin and history

S. affinis originates from central and northern China.<ref name=":0" /> It had been cultivated in China by the 13th century.<ref>Template:Cite journal</ref>

Before S. affinis was introduced to Europe, a related crop named S. palustris was collected in nature to be consumed as a vegetable. Later on the Germanic peoples used S. recta, another relative of S. affinis, as a medicinal plant. The plant was then cultivated from the 18th century onwards. In 1882 the crop was cultivated on a farm for the first time in Crosne.<ref>Template:Citation</ref> S. affinis is the only labiate which is cultivated as vegetable in Europe. At the beginning of the 20th century S. affinis became more and more popular until it was abandoned again in the 1970s due to problems with viruses and the plant's strong vagility (tendency to spread).<ref>Template:Citation</ref><ref>Template:Citation</ref> Since 1990 there has been a rise in the cultivation of S. affinis with availability in some markets and grocery stores. The plant is listed in the "Handbook of Alien Species in Europe" as an invasive plant in Europe.<ref>Template:Citation</ref>

Taxonomy

The plant is part of the family Lamiaceae. A later described species, named S. sieboldii, in dedication to the German-Dutch botanist and japanologist Philipp Franz von Siebold, is considered to be a synonym.

Cultivation

File:Crosnes.jpg

Tubers of S. affinis

S. affinis is planted as a bulb (vegetative) in spring (March–May). Multiple bulbs are planted Template:Convert deep into a hole of dimensions Template:Convert. The plant can achieve a height of Template:Convert. Weeding is necessary but it is important not to damage the root system. A sufficient water supply during summer is important.<ref>Template:Cite book</ref>

Harvest is from November to March. It is important that the soil is not frozen when harvesting.<ref>Template:Cite book</ref>

The storage of S. affinis tubers is difficult. Because of their thin skin, they can be stored only for a few days, about a week in a fridge. An alternative can be a fresh ongoing harvesting out of humid sand, thereby the tubers stay fresh for several months.

Usage

Culinary

File:梅酢で漬けた紅色のちょろぎ.jpg

Pickled, dyed chorogi in Japan

The tubers have a crunchy texture and a sweet, nutty flavour. They can be eaten raw, pickled, dried or cooked.<ref name=":0" /> A wide range of uses for this vegetable leads to various dishes in the cuisine of many countries.<ref>Template:Cite book</ref> They can be prepared similarly to Jerusalem artichokes. The leaves can be dried and made into a tea.

In Chinese and Japanese cuisine, S. affinis is primarily pickled. In particular, its tuber is a part of Template:Transliteration, cooked for celebrating Japanese New Year.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Dyed red by leaves of Perilla (red Template:Transliteration) after being pickled,<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> it is called Template:Transliteration.<ref>Template:Cite book</ref><ref>Template:Cite book</ref> In Korea it is called Template:Transliteration ({{#invoke:Lang|lang}}).

In French cuisine, its cooked tuber is often served alongside dishes named japonaise or Japanese-styled.

Medicinal

In traditional Chinese medicine, the entirety of S. affinis is used as an agent to treat colds and pneumonia.<ref>Template:Cite journal</ref>

In addition, root extract of S. affinis has shown antimicrobial activity.<ref>Template:Cite journal</ref> Furthermore, Baek et al. observed 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 of feeding with methanolic extracts of S. affinis.<ref>Template:Cite journal</ref> Ethanol extract from this plant also seems to have antitumour activity.<ref>Template:Cite journal</ref>

External links

• Stachys affinis in Plants for a Future database
• Template:Grocers
• Crosnes