Perilla frutescens (L.) Britt. (syn. Perilla nankinensis (Lour.) Decne.^[1], etc.) is a cultivated plant of the mint family Lamiaceae. It is the species identification encompassing two distinct varieties^[2] of traditional crop in East Asia:

1. ) P. frutescens var. crispa, the aromatic leafy herb called by its Japanese name shiso, which in turn is a loan word from the Chinese: 紫蘇; pinyin: zi-su; Wade–Giles: tsu-su^[3]. The plant occurs in red (purple-leaved) or green-leaved forms. The now less fashionable English name "beefsteak plant" has been superseded by the Japanese-derived name shiso in the mass media and popular literature^[4].
2. ) P. frutescens var. frutescens or var. japonica, the oilseed crop, source of perilla oil and a common food ingredient in Korean cuisine, both as "wild sesame" in seed form, and as "sesame leaves". The provisional English name "wild sesame" is a literal translation of the Korean name Hangul: 들깨; RR: deulggae; MR: tŭlkkae. In Japan this type of perilla is called egoma (エゴマ or 荏胡麻^?) (from 荏, Japanese: e-; Chinese: 荏; pinyin: ren; Wade–Giles: jen^[5]; Korean: 임 im), and is not shiso.
   

The genus name perilla is also a frequently used as the common plant name^[6][7], but that may be confusing since it is applicable to both varieties.

Description

The two cultivated varietal groups has a history of being treated as two species, though it was recognized hat they readily crosspolinated. Though now lumped into a single species of polytypic character, the two cultigens continue to be regarded as two distinct commodities in the Asian market where they are most exploited. While they are morphologically similar, the modern strains are readily distinguishable. Accordingly description should be given separately or compartively for the culitvars.

Foliage

Shiso plant with forming leaves, stem and leaf detail

var. japonica seen grown in Korea

As a case in point, both varieties have foliage that outwardly look similar: broad ovate leaves which are serrate, arranged opposite^[8]. But the green shiso leaf (pictured top left) is easily differentiated from "sesame leaf" of the same color (Korean: Hangul: 깻잎; RR: ggaenip; MR: kkaenip; pictured left) by taste and fragrance. The shiso's distinctive flavor comes from its perillaldehyde component^[9], present only in low concentration in the wild sesame foliage. Meanwhile, Korean investigators in recent years found that in the Korean perilla, the most active aroma compounds were perilla ketone, (Z)-3-hexenal (green), egoma ketone and isoegoma ketone^[10].

The red (purple) forms of the shiso (forma purpurea and crispa) comes from its pigment, called "perilla anthocyanin " or shisonin anthocyanin^[11]. The color is present in both sides of the leaves, as well as the entire stalk, and flower buds (calyxes).

The red crinkly or ruffled leafed strain (called chirimenjiso in Japan; forma crispa) was the shiso first examined by Western botany, and Thunberg named it P. crispa (the name meaning "wavy or curly"). That Latin name was later retained when this form of shiso was reclassed as a variety.

There are also bi-colored cultivars (var. Crispa forma discolor Makino; カタメンジソ (katamenjiso^?)^[12]) which are only red on the bottom (see pictured, top right). The crinkly-leafed (or crepey-leafed) type also comes not just in red, but also in a green-leaved form (chirimenaojiso, forma viridi-crispa).

Sizes and seeds

It has been noted that the wild sesame grows taller (60~150 cm^[13] ) and yield larger softer seeds, while the shiso are shorter (40~100 cm?) and produce harder smaller grains of seed^[2][14][15].

Citable source for diameter difference is wanting, but comparison of seeds by mass shows shiso to weigh about 1.5g per 1000 seeds ^[16], whereas the oilseed weighs 4g per 1000 seeds^[17].

The flawed assertion that "the seeds are difficult to distinguish even by scanning electron microscope" is taken out of context, since the original source ^[18] actually discusses the carbonized grain excavated lodged in crumbs of breadlike food excavated from Yayoi period or even Jōmon period strata^[19].

Origins and distribution

Suggested native origins are mountainous terrains of India and China^[20], although some books say Southeast Asia^[1].

It spread thorought China some time in remote antiquity. One of the early mentions on record occurs in Renown Physician's Extra Records (Chinese: "Ming Yi Bie Lu" 名医别录; pinyin: Ming Yi Bie Lu), ca. 500 AD. ^[21], where it is listed as su(蘇), and some of its uses are described.

The perilla was introduced into Japan around the 8th to 9th century^[22] This seemingly contradicts the finds of carbonized grains stated earlier from prehistoric archeological sites, but since they are inconclusive about the species they examined, endemic species such as P. citrodora cannot be ruled out from what they found.

The species was introduced into the Western horticulture as an ornamental^[8], and in the United States became naturalized and established in a widespread area^[8], and may be considered weedy or invasive.

Taxa and synonyma

The classification Perilla is confused^[23][24], partly because botanist struggled with how to distinguish the two distinct cultigens (as different spp. or varr.).

An early example of dividing the two cultigens into different species is found in Matsumura's nomenclature book in 1884^[25], where the synonym P. arguta Benth.^[26][20] is applied to shiso, and the synonym P. ocymoides L.^[1][20] was applied to the oilseed perilla.

The species name P. ocymoides or P. ocimoides has been used to denote the oilseed variety for a long time, especially by the Japanese^[27], so it should not be considered a synomym for either cultigen interchangebly.

It is well-established that the two varieties are cross-fertile^[2]. It has been cautioned that the desired essential oil yield will be compromised if the seed for sowing becomes hybridized, and that "it is very difficult to distinguish genuine perilla seed from hybrid seed", ^[28]. In another words, the escaped types no longer retain the distinctive shiso fragance, and are not fit for cosumption, so bastardized seeds becom of reduced quality.

English common names

The scarlet-leaved form of shiso was introduced into the West, around the 1850's^[29], when the ornamental variety was usually referred to as P. Nankinensis. This red-leafed border plant eventually earned the English-language name "beefsteak plant"^[30]. This was the English equivalent name was in standard usage over a period, authoritative Kenkyūsha's New Japanese-English Dictionary^[31]. Due to that legacy, the old-fashioned name remains in circulation today^[6]

Other common names are: "perilla mint"^[32], "Chinese basil"^[6][33][26], or "wild basil"^[6] are in use as well.

The alias "wild coleus"^[34] or "summer coleus"^[6] probably describe ornamental varieties.

The red shiso or su tzu types are called purple mint^[6] or purple mint plant ^[35].

It is also called rattlesnake weed^[6] in the Ozarks, because the sound that the dried stalks make when disturbed along the footpath is reminiscent of the rattlesnake rattler sound^[36].

Economic uses

Its leaves and other parts are used as foods in China, Japan and Korea. Perilla oil is used in Korean cuisine, as well as industrially. Th plant has also been used in traditional Chinese medicine for more than two thousand years.

Culinary use

The red perilla has red leaves and used mostly in fish stews in China. Koreans make pickled "wild sesame" perilla leaves with red chili powder and soy sauce. Oil extracted from P. frutescens var. frutescens "is still used to cover cookies in rural areas of Korea"^[37]. Sometimes, the seeds are ground and added to soup for seasoning in Korea.

The Japanese shiso leaves come in green, red, and also bicolored, and crinkly (chirimen-jiso) varieties, as noted. Parts of the plants eaten are the leaves, flower and buds from the flower stalks, fruits and seeds (mericarp), and sprouts.

Japanese use green shiso leaves raw with sashimi. Dried leaves are also infused to make tea^{[citation needed]}. The red shiso leaf is not normally consumed fresh, but needs to be e.g. cured in salt. The pigment in the leaves turn from purple to bright red color when steeped in umezu, and is used to color and flavor umeboshi.

Industrial use of oil

Until around the Sengoku period (early 16th century) in Japan, perilla oil was important for fueling oil lamps^[38], until being was overtaken by rapeseed oil.

The oilseed contains drying oil elements and imported in bulk as a substitute for linseed oil into the United States from Japan, until the supply was interrupted by war^[39].

Ornamental use

The red-leaved shiso, in earlier literature referred to as P. Nankinensis, became available to gardening enthusiasts in England ca. 1855^[29]. By 1862, the English were reporting overuse of this plant, and proposing the Coleus Vershaeffeltii ^[40] or the "Amaranthus melancholicus var. Ruber made available by J. G. Veitch ^[41] as an alternative.

It was introduced later in the United States, perhaps in the 1860's^[42][43].

Chemical composition

The oilseed variety contains about 38-45% lipid^[44]. Expressed from these seeds, the perilla oil exhibits one of the highest proportions of omega-3 (α-linolenic acid (ALA)^[6]fatty acids of any seed oil, at 54-64% and only 14% linoleic acid, an omega-6 fatty acid. This unusual n6:n3 ratio gives this crop potential for an alternative to other seed oils, one with potential to lower risk for multiple chronic diseases. ^[45]

The Japanese type (i.e. shiso) contain only about 25.2-25.7% lipid ^[46], but still contain a comparable 60% ratio of ALA fatty acid^[47][48].

References

Sources

(herbs and food plant handbooks)

• Boning, Charles R. (2010) (preview), Florida's Best Herbs and Spices, London: Pineapple Press Inc, pp. 148-, ISBN [[Special:BookSources/781561644537|781561644537]], http://books.google.co.jp/books?id=uTIoxgzULJcC&pg=148 
• Roecklein, John C.; Leung, PingSun (1987) (preview), A Profile of Economic Plants, Transaction Publishers, p. 349, ISBN 978-0-88738-167-6, http://books.google.co.jp/books?id=C8eRalwPua0C&pg=PA349 
• Staples, George W.; Kristiansen, Michael S. (1999), Ethnic culinary herbs: A guide to identification and cultivation in Hawaii, Honolulu: University of Hawaii Press, pp. 82-, ISBN 978-0-8248-2094-7, http://books.google.com/books?id=jbsdYHEJiDIC 
• Tucker, Arthur O.; DeBaggio, Thomas (2009) (preview), The Encyclopedia of Herbs: a comprehensive reference to herbs of flavor and, Timber Press, p. 389, ISBN 978-0-88192-994-2, http://books.google.co.jp/books?id=7_KPgxEglHAC&pg=PA389 
• Vaughan, John Griffith; Geissler, Catherine (2009). The new Oxford book of food plants. Oxford: Oxford University Press. p. 152. ISBN 978-0-19-954946-7. http://books.google.com/books?id=UdKxFcen8zgC. 

(monogram on species)

• Anderson, Edgar (1970), "The Tangled Career of Perilla Frutescens" (snippet), Oecology issue (Io): 31, http://books.google.co.jp/books?id=R4woAQAAIAAJ 
• Nitta, Miyuki; Lee, Ju Kyong; Ohnishi, Ohmi (2003), "Asian Perilla Crops and Their Weedy Forms: Their Cultivation, Utilization and Genetic Relationships", Economic Botany (New York Botanical Garden Press) 57 (2): 245-253, JSTOR 4256682 
• Yu, He-Ci; Kosuna, Kenichi; Haga, Megumi (1997) (preview), Perilla: the genus Perilla, CRC Press, ISBN 978-90-5702-171-8, http://books.google.co.jp/books?id=M5A71gsWUskC 
• Zeevaart, Jan A. D. (1969), L. T., ed., "Perilla spp.", The Induction of Flowering 

(nomenclature, taxonomy)

• Matsumura, Jinzō (1884) (google), Nippon Shokubutsumei, or nomenclature of Japanese plants in Latin, Japanese and Chinese(日本植物名彙), Tokyo: Z.P. Maruya, pp. 136, http://books.google.co.jp/books?id=IOIlAQAAMAAJ&pg=PA136 
• Kays, Stanley J. (2011) (preview), Cultivated vegetables of the world: a multilingual onomasticon, Wageningen Academic Pub., pp. 180-1, 677-8, ISBN 978-90-8686-164-4, http://books.google.co.jp/books?id=9c7LggdxjBcC&pg=PA677 

(chemistry)

• Blaschek, Wolfgang; Hänsel, Rudolf; Keller, Konstantin (1998) (preview), Hagers Handbuch der Pharmazeutischen Praxis, 3 (L-Z), Gabler Wissenschaftsverlage, pp. 328-, ISBN 978-3-540-61619-1, http://books.google.co.jp/books?id=XGXnVRiu3zoC&pg=PA328 
• Guenther, Ernest (1949) (snippet), The Essential Oils, Cambridge and New York: D. Van Nostrand Co., pp. 687-, http://books.google.co.jp/books?id=A4drAAAAIAAJ 
• Seo, Won Ho; Baek, Hyung Hee (2009), "Characteristic Aroma-Active Compounds of Korean Perilla (Perilla frutescens Britton) Leaf", Journal of Agriculture and Food Chemistry 57 (24): 11537–11542, doi:10.1021/jf902669d 
• Wilson, BJ; Garst, JE; Linnabary, RD; Channell, RB (5 August 1977), "Perilla ketone: a potent lung toxin from the mint plant, Perilla frutescens Britton", Science 197 (4303): 573-574 
  

(Chinese perspective)

• Foster, Steven; Yue, Chongxi (1992) (preview), Herbal emissaries: bringing Chinese herbs to the West : a guide to gardening, Inner Traditions / Bear & Co., pp. 306-8 
• Hu, Shiu-ying (2005) (preview), Food plants of China, 1, Chinese University Press, http://books.google.co.jp/books?id=2OiYydyrsygC&pg=PA503 

(Korean)

• Gale, James Scarth (1897) (google), A Korean-English dictionary, Kelly & Walsh, pp. 611,661, http://books.google.co.jp/books?id=ix4TAAAAYAAJ 

(Japanese)

• Heibonsha (1964), 世界百科事典(Sekai hyakka jiten)  (world encyclopedia, in Japanese).
• Oikawa, Kazushi; Toyama, Ryo (2008), "Analysis of Nutrition and the Functionality Elements in Perilla Seeds", 岩手県工業センター研究報告 15  pdf (in Japanese except abstract)
• Hiroi, Masaru (広井勝) (2010), "エゴマの成分と利用", 特産種苗 5  [tokusanshubyo.sakura.ne.jp/jouhoushi05/j05-13.pdf pdf] (in Japanese except abstract)

(paleoethnobotany)

• Imamura, Keiji (1996) (preview), Prehistoric Japan - New Perspectives on Insular East Asia, Honolulu: University of Hawaii Press, pp. 107-8, http://books.google.com/books?id=HpgcaKpnuU0C&pg=PA107 
• Habu, Junko (2004) (preview), Ancient Jomon of Japan, Cambridge and New York: Cambridge Press, p. 59, http://books.google.co.jp/books?id=vGnAbTyTynsC&pg=PA59