Senna obtusifolia, known by the common names Chinese senna, American sicklepod, sicklepod, etc., is a plant in the genus Senna, sometimes separated in the monotypic genus Diallobus. It grows wild in North, Central, and South America, Asia, Africa, and Oceania, and is considered a particularly problematic weed in many places. It has a long-standing history of confusion with Senna tora and that taxon in many sources actually refers to the present species.

Senna obtusifolia

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Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Fabales
Family: Fabaceae
Subfamily: Caesalpinioideae
Genus: Senna
S. obtusifolia
Binomial name
Senna obtusifolia
  • Cassia obtusifolia L.
  • Cassia tora var. obtusifolia (L.) Haines
  • Emelista obtusifolia (L.) Raf.
  • Senna tora var. obtusifolia (L.) X.Y.Zhu
  • Cassia rogeonii Ghesq.
  • Cassia tora var. humilis Pers.
  • Cassia toroides Raf.
  • Senna toroides Roxb.

In the traditional medicine of Eastern Asia, the seeds are called jué míng zǐ in Chinese (simplified: 决明子; traditional: 決明子), gyeolmyeongja in Korean, and ketsumeishi in Japanese.

The green leaves of the plant are fermented to produce a high-protein food product called kawal which is eaten by many people in Sudan as a meat substitute. Its leaves, seeds, and root are also used in folk medicine, primarily in Asia. It is believed to possess a laxative effect, as well as to be beneficial for the eyes. As a folk remedy, the seeds are often roasted, then boiled in water to produce a tea. The plant's seeds are a commercial source of cassia gum, a food additive usually used as a thickener and named for the Chinese Senna's former placement in the genus Cassia. Roasted and ground, the seeds have also been used as a substitute for coffee. In vitro cultures of S. obtusifolia such as hairy roots may be a source of valuable secondary metabolites with medical applications.[3]

Taxonomy and naming


This species was first formally described in 1753 by Carl Linnaeus who gave it the name Cassia obtusifolia in Species Plantarum.[4][5] In 1979, Howard Samuel Irwin and Rupert Charles Barneby transferred the species to the genus Senna as S. obtusifolia in the Memoirs of the New York Botanical Garden.[6][7] The specific epithet (obtusifolia) means "blunt-leaved".[8]

S. obtusifolia is known by a number of common names. Apart from "sicklepod",[9] sickle-pod senna,[10] rarely "Chinese senna"[11] or even "American sicklepod",[12] it is also called arsenic weed,[13] foetid cassia, or wild senna.[10]

It is also known locally by common names such as "coffee weed" (coffeeweed)[14] or "java bean" (in Australia)[14] or "coffee pod" (in the American South or West),[15][13] although the terms "coffee weed" or "coffee pod" are ambiguous as they also apply to S. tora.[9] It may be called by the Hindi name "chakunda" in India, but this is also one of the names for S. tora.[9]

Names in its native range are also:

Distribution and habitat


Senna obtusifolia is endemic to Central America and South America, but is naturalised in North America, Africa, parts of Europe, the Middle East, the Indian subcontinent, parts of Southeast Asia, New Guinea and parts of Australia.[2] In its natural environment, it grows on the shores of lakes and rivers, but is also a weed of pastures and roadsides at altitudes up to 1,100 m (3,600 ft).[7]

Traditional Eastern medicine


The materia medica name for the seeds in Chinese is jué míng zǐ (simplified: 决明子; traditional: 決明子).[19] The medicinal seeds are also known by the equivalent Korean name gyeolmyeongja (결명자; 決明子) in traditional Korean medicine,[20] and by the Japanese name ketsumei-shi (ケツメイシ, 決明子) in kampō medicine.[21]

The jue ming zi is used widely in Asia, including Southeast Asian countries such as Thailand,[21][22] and its herbal tea is drunk instead of regular tea as a preventative for hypertension.[21][22] It is also purported to have the ability to clear the eye.[21] In Korea also, medicinal gyeolmyeongja is usually prepared as tea (gyeolmyeongja-cha. ‘sickle pod tea’).

Senna tora (Cassia tora) is used similarly, and though distinguished in the Chinese market as the "little/lesser" variety or shao jue ming 小決明)[22] the Japanese government's [pharmacopoeia] (Nihon yakkyokuhō) officially acknowledges both S. obtusifolia and S. tora to be commerced as ketsumeishi.[22]

The Japanese beverage habu-cha (ハブ茶), as the name suggests, was originally brewed from the seeds of the habusō or S. occidentalis, but currently marketed habu-cha uses S. obtusifolia as substitute, since it is a higher-yielding crop.[23][24]

Western medicine


The antimicrobial activity of leaf extracts of Senna obtusifolia have been studied.[25]

Meat substitute


Kawal, a protein-rich meat substitute eaten in Sudan, is produced by crushing the leaves of the plant into a paste which is then traditionally fermented in an earthenware jar, buried in a cool place. The jar is dug up every three days and the contents mixed. After two weeks, the paste is removed and rolled into balls which are left to dry in the sun. They are usually cooked in stews with onions and okra.[26][27]

See also



  1. ^ Bachman, S. (2018). "Senna obtusifolia". IUCN Red List of Threatened Species. 2018: e.T19375580A122395452. Retrieved 14 November 2022.
  2. ^ a b c "Senna obtusifolia". Plants of the World Online. Retrieved 12 August 2023.
  3. ^ Kowalczyk, Tomasz; Sitarek, Przemysław; Toma, Monika; Picot, Laurent; Wielanek, Marzena; Skała, Ewa; Śliwiński, Tomasz (2020-03-27). "An Extract of Transgenic Senna obtusifolia L. hairy roots with Overexpression of PgSS1 Gene in Combination with Chemotherapeutic Agent Induces Apoptosis in the Leukemia Cell Line". Biomolecules. 10 (4): 510. doi:10.3390/biom10040510. ISSN 2218-273X. PMC 7226363. PMID 32230928.
  4. ^ "Senna obtusifolia". Australian Plant Name Index. Retrieved 12 August 2023.
  5. ^ Linnaeus, Carl (1753). Species Plantarum. Vol. 1. Berlin: Junk. p. 377. Retrieved 12 August 2023.
  6. ^ "Senna obtusifolia". Australian Plant Name Index. Retrieved 12 August 2023.
  7. ^ a b Irwin, Howard S.; Barneby, Rupert C. (1982). "The American Cassiinae : a synoptical revision of Leguminosae tribe Cassieae subtribe Casiinae in the New World". Memoirs of the New York Botanical Garden. 35 (1): 252–255. Retrieved 12 August 2023.
  8. ^ Sharr, Francis Aubi; George, Alex (2019). Western Australian Plant Names and Their Meanings (3rd ed.). Kardinya, WA: Four Gables Press. p. 263. ISBN 9780958034180.
  9. ^ a b c CRC World Dictionary of Plant Names: Common Names, Scientific Names, Eponyms. Synonyms, and Etymology. Vol. 4. 1999. pp. 2460, 2461. ISBN 9780849326783.
  10. ^ a b c Gardner, Zoë; McGuffin, Michael (2013). American Herbal Products Association's Botanical Safety Handbook (2 ed.). CRC Press. p. 804. ISBN 9781466516946.
  11. ^ Library of Congress Subject Headings. Library of Congress, Cataloging Distribution Service. 2009. p. 1449.
  12. ^ BSBI List 2007 (xls). Botanical Society of Britain and Ireland. Archived from the original (xls) on 2015-06-26. Retrieved 2014-10-17.
  13. ^ a b DiTomaso, Joseph M. (2007). Weeds of California and Other Western States: Aizoaceae-Fabaceae. University of California Division of Agriculture and Natural Resources. p. 800. ISBN 9781879906693.
  14. ^ a b "Senna obtusifolia (sicklepod)". CABI—Invasive Species Compendium. 21 November 2019. Retrieved 20 December 2020.
  15. ^ Gibbons, Whit; Haynes, Robert R.; Geller, Robert J. (1990). Poisonous Plants and Venomous Animals of Alabama and Adjoining States. Joab L. Thomas (foreword). University of Alabama Press. p. 102. ISBN 9780817304423.
  16. ^ Yan, Kun-ying (1970). Chángyòng zhōngyào zhī yàolǐ 常用中藥之藥理. Vol. 5. Taipei: Guo li Zhongguo yi yao yan jiu suo. p. 800. ISBN 9789570094169.
  17. ^ Balick, Michael J. (2009). Ethnobotany of Pohnpei: Plants, People, and Island Culture. University of Hawaii Press. p. 394. ISBN 9780824837495.
  18. ^ Mori, Akihiko (2020). "Kika & gairai shokubutsu miwake manyuaru 950shu" 帰化&外来植物見分け方マニュアル950種 (in Japanese). 7 (1). Shuwa System: 224. ISBN 9784798057927. {{cite journal}}: Cite journal requires |journal= (help)
  19. ^ Chang, Zhangfu; Liu, Li; Bare, James (2015). Chinese Materia Medica. PMPH-USA. pp. 123–124. ISBN 9787117196475.
  20. ^ Kim, Taejung (1996). Yag-idoeneunhangug-uisan-yacho 약이되는한국의산야초 [Korea's wild plants as medicine] (in Korean). Kugil Media. p. 88. ISBN 9788974250751.
  21. ^ a b c d Wang, Yuan; Sheir, Warren; Ono, Mika (2010). Ancient Wisdom, Modern Kitchen: Recipes from the East for Health, Healing, and Long Life. Hachette Books. p. 23. ISBN 9780738214054.
  22. ^ a b c d Kijima, Masao (1969). "Tai koku shōyaku no kōsatsu III" <報告>タイ国生薬の考察 III [Observations III on herbal medicine in Thailand]. Japanese Journal of Southeast Asian Studies (in Japanese). 7 (1): 78–79. hdl:2433/55564.
  23. ^ Okada, Minoru; Wada, Hiroshi (2002). Shintei genshoku makino wakan yakusō daizukan 新訂原色牧野和漢薬草大圖鑑 [New edition of Makino's great encyclopedia of Japanese and Chinese medicinal herbs in original color] (in Japanese). Hokuryukan. pp. 204, 205. ISBN 9784832608108.
  24. ^ Tōhō University, Yakugakubu fuzoku yakuyō shokubutsuen (medicinal herbarium attached to pharmacology dept.) (May 2019). "Ebsisugusa" エビスグサ. Yakuyō shokubutsuen mihon-en 薬用植物園 見本園 (in Japanese). Retrieved 2020-12-19.
  25. ^ Doughari, J.H.; El-Mahmood, A.M.; Tyoyina, S.P. (2008). "Antmicrobial activity of leaf extracts of Senna obtusifolia". African Journal of Pharmaceuticals and Pharmacology. 2: 7-13.
  26. ^ Dirar, Hamid (1 July 1984). "Kawal, meat substitute from fermented Cassia obtusifolia leaves". Economic Botany. 38 (3): 342–349. doi:10.1007/bf02859013. JSTOR 3793107. S2CID 32446384.
  27. ^ "Plants that provide a protein-rich diet". New Scientist. 107 (1468): 30. 8 August 1985. ISSN 0028-6664.