Zanthoxylum piperitum

This article is about Japanese pepper. For Chinese or Szechuan pepper, see Sichuan pepper.

Japanese pepper, Japanese pricklyash
Zanthoxylum piperitum
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Rosids
Order:	Sapindales
Family:	Rutaceae
Genus:	Zanthoxylum
Species:	Z. piperitum
Binomial name
Zanthoxylum piperitum (L.) DC

Fruit and seeds

Zanthoxylum piperitum, the Japanese pepper, Japanese pricklyash, or sanshō (Japanese: 山椒) is a deciduous aromatic spiny shrub or small tree, belonging to the Rutaceae (citrus and rue) family. Natural range spans from Hokkaido to Kyushu in Japan, southern parts of the Korean peninsula, and Chinese mainland. The related Z. schinifolium (Japanese: イヌザンショウ pron. inuzanshō, lit., "dog sansho") occurs as far south as Yakushima, attaining a height of 3 meters.

The plant is important commercially. The pulverized mature fruits ("peppercorns" or "berries") known as "Japanese pepper" or kona-zanshō (Japanese: 粉ざんしょう) are the standard spice for sprinkling on the broiled eel (kabayaki unagi) dish. It is also one of the seven main ingredients of the blended spice called shichimi, which also contains red chili peppers.

It is also a host plant for several of Japan indigenous swallowtail butterfly species, including the common Papilio xuthus.

Description

The tree blooms in April to May, forming axillary flower clusters, about 5mm, and yellow-green in color. It is dioecious, and the flowers of the male plant can be consumed as hana-sanshō, while the female flowers yield berries or peppercorns of about 5mm. For commercial harvesting, thornless varieties called the Asakura sansho are widely cultivated. Around September to October, the berries turn scarlet and burst, scattering the black seeds within.

The branch grows pairs of sharp thorns, and has odd-pinnately compound leaves, alternately arranged, with 5〜9 pairs of ovate leaflets having crenate (slightly serrated) margins.

Culinary uses

The finely ground Japanese pepper, kona-zanshō, is nowadays usually sold in sealed packets, and individual serving sizes are included inside heat-and-serve broiled eel packages. While red chili pepper is never used on eel, otherwise, in many usages, the Japanese red chili pepper, or the shichimi blend of peppers can be used in lieu of Japanese pepper alone, according to taste: e.g., to flavor miso soup, various noodles in broth or dipped in tsuyu, Japanese pickles (tsukemono), teriyaki or fried chicken.

Young leaves and shoots, pronounced ki no mé or ko no mé (Japanese: 木の芽 lit. "tree-bud") herald the spring season, and often garnish grilled fish and soups. They have a distinctive flavor and is not to the liking of everyone. It is a customary ritual to put a leaf between cupped hands, and clap the hands with a popping sound, this supposedly serving to bring out the aroma. The young leaves are crushed and blended with miso using pestle and mortar (suribachi and surikogi) to make a paste, a pesto sauce of sorts, and then used to make various aemono (or "tossed salad", for lack of a better word). The stereotypical main ingredient for the resultant kinome-ae is the fresh harvest of bamboo shoots, but the sauce may be tossed (or delicately "folded", to use a pastrymaking term) into sashimi, clams, squid or other vegetable such as tara-no-me (Aralia elata shoots).

Fresh green Japanese pepper in a supermarket in Japan

The immature green berries, blanched and salted, are called ao-zanshō (lit. "green sansho"). The berries are traditionally simmered into dark-brown tsukudani, but nowadays are also available as shoyu-zuke, which is just steeped in soy sauce. The berries are also cooked with small fry fish and flavored with soy sauce ([[{{{1}}}]]), a specialty item of Kyoto, since its Mount Kurama outskirts is a renowned growing area of the Japanese pepper.

The thornless variety Asakura sansho derives its name from its place of origin, the Asakura district in the now defunct [[{{{1}}}]], integrated into Yabu, Hyōgo.

Wakayama Prefecture boasts 80% of domestic production. Aridagawa, Wakayama procuces a specialty variety called budō sanshō ("grape sansho"), which bears large fruits and clusters, rather like a bunch of grapes.

Confections

In central and northeastern Japan, a non-sticky rice-cake type confection called [[{{{1}}}]], which is basted with miso-based paste and grilled, sometimes uses the Japanese pepper as flavor additive to the miso. Also being marketed are sansho flavored arare (rice crackers), snack foods, and sweet sansho-mochi.

Timber uses

The thick wood of the tree is traditionally made into a gnarled and rough-hewn wooden pestle, to use with the aforementioned suribachi.

Pharmaceutical uses

The husks are used medicinally. In traditional Chinese medicine it finds uses similar to the hua jiao or Sichuan pepper

In Japanese pharmaceuticals, the mature husks with seeds removed are considered the crude medicine form of sanshō. It is an ingredient in lange. It also contains aromatic oils geraniol, dipentene, citral, etc.

See also

• Sichuan pepper