Senna obtusifolia, known by common names including Chinese senna, American sicklepod and sicklepod, is a plant in the genusSenna, 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.
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 sicklepod 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]
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]
Senna obtusifoliaisendemic 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]
The jue ming zi is used widely in Asia, including Southeast Asian countries such as Thailand,[21][22] and its herbal sicklepod 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 habusōorS. occidentalis, but currently marketed habu-cha uses S. obtusifolia as substitute, since it is a higher-yielding crop.[23][24]
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]
^Sharr, Francis Aubi; George, Alex (2019). Western Australian Plant Names and Their Meanings (3rd ed.). Kardinya, WA: Four Gables Press. p. 263. ISBN9780958034180.
