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.

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.

[4][5] 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.

[6] 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.

[9][10] 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.