Leucas zeylanica

Classification System: APG IV

Superregnum: Eukaryota
Regnum: Plantae
Cladus: Angiosperms
Cladus: Eudicots
Cladus: Core eudicots
Cladus: Asterids
Cladus: Lamiids
Ordo: Lamiales

Familia: Lamiaceae
Subfamilia: Lamioideae
Tribus: Leucadeae
Genus: Leucas
Species: Leucas zeylanica
Varieties: L. z. var. walkeri – L. z. var. zeylanica
Name

Leucas zeylanica (L.) W.T.Aiton, 1811
Synonyms

Basionym
Phlomis zeylanica L., Sp. Pl.: 586 (1753).
Homotypic
Phlomis gracilis (L.) Salisb., Prodr. Stirp. Chap. Allerton: 84 (1796), nom. superfl.
Leucasia zeylanica (L.) Raf., Fl. Tellur. 3: 88 (1837).

Distribution
Native distribution areas:

Continental: Asia-Temperate
Regional: Indian subcontinent
Assam, Bangladesh, East Himalaya, India, Nepal, Sri Lanka, West Himalaya
Regional: Indian subcontinent
China Southeast, Hainan
Continental: Asia-Tropical
Regional: Southeastern asia
Borneo, Cambodia, Christmas I., Jawa, Lesser Sunda Is., Malaya, Maluku, Myanmar, New Guinea, Philippines, Sumatera, Thailand, Vietnam
Introduced into:
Maldives, Mauritius, Queensland

References: Brummitt, R.K. 2001. TDWG – World Geographical Scheme for Recording Plant Distributions, 2nd Edition
References
Primary references

Aiton, W.T. 1811. Hortus Kewensis; or, a Catalogue of the Plants Cultivated in the Royal Botanic Garden at Kew. 2nd Edn., Vol. III, iii + 432 pp. Longman, Hurst, Rees, Orme, and Brown, London. BHL. Reference page. : ed. 2, 3:409.

Additional references

Govaerts, R.H.A. 2003. World Checklist of Selected Plant Families Database in ACCESS: 1-216203. The Board of Trustees of the Royal Botanic Gardens, Kew. [unavailable for the public] Reference page.

Links

Govaerts, R. et al. 2022. Leucas zeylanica in World Checklist of Selected Plant Families. The Board of Trustees of the Royal Botanic Gardens, Kew. Published online. Accessed: 2022 Mar 27. Reference page.
Hassler, M. 2022. Leucas zeylanica. World Plants: Synonymic Checklists of the Vascular Plants of the World In: Roskovh, Y., Abucay, L., Orrell, T., Nicolson, D., Bailly, N., Kirk, P., Bourgoin, T., DeWalt, R.E., Decock, W., De Wever, A., Nieukerken, E. van, Zarucchi, J. & Penev, L., eds. 2022. Species 2000 & ITIS Catalogue of Life. Published online. Accessed: 2022 Mar 27. Reference page.
Tropicos.org 2022. Leucas zeylanica. Missouri Botanical Garden. Published online. Accessed: 27 Mar 2022.
International Plant Names Index. 2022. Leucas zeylanica. Published online. Accessed: Mar 27 2022.
USDA, ARS, Germplasm Resources Information Network. Leucas zeylanica in the Germplasm Resources Information Network (GRIN), U.S. Department of Agriculture Agricultural Research Service. Accessed: 07-Oct-06.

Vernacular names

Leucas zeylanica, commonly known as Ceylon slitwort,[1] is a small, terrestrial, herbaceous, annual, erect or sometimes tufted, hispid and aromatic plant of the subfamily Lamioideae of family Lamiaceae. It is native to tropical Asia.[2][3]

Description

The plant grows to a height of up to 120 cm (47 in). Stipules are absent, the taproot is white or brown, and the stem is quadrangular. Sub-sessile leaves are linear-lanceolate or elliptic-lanceolate, 2.5–7.5 cm (0.98–2.95 in) long, not lobed or divided, blunt at the tip, obtuse, entire or cerrulate, glandular, hispid and coarsely dentate at the margins. Whorls of many flowers are bisexual, sessile or sub-sessile, usually in terminal whorls 1–2 cm (0.39–0.79 in) in diameter, grouped together in an axillary, corolla white in color and 2 cm long. Calyx is 5–7 mm (0.20–0.28 in) long, and obliquely turbinate, with minute teeth, apex acute, base acute, pinnately veined, erect or spreading horizontally. It is reproduced by seed and pollinated by bees moths and flies. Leucas belongs to the subfamily Lamioideae, and is closely related to the small genera Acrotome and Leonotis.[4][5]
Habitat

Plant occurs in various habitats, a weed of sunny dry localities, often on sandy soils, paddy dams, waste places, open grasslands, road-sides from the lowland up to 1,700 m (5,600 ft) in altitude. It is widely distributed throughout Southeast Asia, but is rather rare in East Asia.[6]
Constituents

A decoction of the herb prepared by boiling with a soda solution emits a strong odor; when condensed, the vapor yields ammonia and a volatile alkaloid in the distillate.
Uses
Culinary

The whole herb has a bitter taste, but is still used as flavoring or potherb.
Traditional medicine

The indigenous tribes in the Satpuda region of Dhule and Jalgaon districts of Maharashtra use L. zeylanicain for fever, jaundice, and for scorpion and snake bites.[7]
Agricultural

Many species in the genus Leucas are becoming serious weeds in rice fields, sugarcane, and banana plantations.
Cultural

The flower of Thumba plant is the central part of Onam festival in Kerala. The tiny flower of the plant is very important for laying Pookkalam.[8]
Essential oil

Leucas zeylanica yields a small amount of essential oil on distillation. The major components are oleic acid, hexadecanoic acid, 1-octen-3-ol, and caryophyllene. It has the ability to inhibit of test bacterial growth, especially Escherichia coli and Salmonella enteritidis.[9][10]
Research

In a study of 32 plants species collected from serpentine (ultramafic) soils in Sri Lanka and screened for antimicrobial properties, L. zeylanica showed photo-mediated activity against Staphylococcus aureus and Bacillus subtilis. L. zeylanica showed population-level variation in photoactivity. Study suggests plants from serpentine environments may have alterered antimicrobial activities compared to non-serpentine environments, and that attention is needed in deciding on the substrate and habitat when collecting plants to test for antimicrobial properties.[11]
References

"Leucas Zeylanica". virboga.de. Retrieved 2012-03-28.
"Leucas Zeylanica List". tropicos.org. Retrieved 2012-03-28.
"The International Plant Name Index - Leucas Zeylanica List". ipni.org. Retrieved 2012-03-28.
"Leucas zeylanica (L.) R.Br. - LAMIACEAE - Dicotyledon". oswaldasia.org. Archived from the original on 2012-05-26. Retrieved 2012-03-28.
"Leucas zeylanica in Flora of China". efloras.org. Retrieved 2012-03-28.
"Leucas zeylanica". Germplasm Resources Information Network (GRIN). Agricultural Research Service (ARS), United States Department of Agriculture (USDA). Retrieved 2012-03-28.
Jain, DL; Baheti, AM; Jain, SR; Khandelwal, KR (2010). "Use of medicinal plants among tribes in Satpuda region of Dhule and Jalgaon districts of Maharashtra–An ethnobotanical survey" (PDF). Indian Journal of Traditional Knowledge. 9 (1): 152–157.
Vijayakumar, Sindhu (August 21, 2015). "The allure of Onappookalam". The Times of India. Retrieved 2022-05-09.
"Study on Essential Oil Obtained from the Seed of Leucas zeylanica". cnki.com.cn. 2009-02-16. Archived from the original on 2016-03-03. Retrieved 2012-03-28.
"Study on Essential Oil Obtained from the Seed of Leucas zeylanica". scienceengineeringonline.com. Archived from the original on 2011-11-01. Retrieved 2012-03-28.
Nishanta Rajakaruna, Cory S. Harris and G.H.N. Towers (2002). "Antimicrobial Activity of Plants Collected from Serpentine Outcrops in Sri Lanka" (PDF). Pharmaceutical Biology. 40 (3): 235–244. doi:10.1076/phbi.40.3.235.5825.