Herb's Introduction
Thunbergia grandiflora (Roxb. ex Rottl.) Roxb., commonly known as the Blue Trumpet Vine or Bengal Clock Vine, is a vigorous, twining, woody, perennial climber belonging to the Acanthaceae family. It is native to regions spanning from Central Nepal to Southern China and Peninsula Malaysia. Valued for its large, striking flowers and lush foliage, it is widely cultivated as an ornamental plant in tropical and subtropical regions. Beyond its aesthetic appeal, it is a plant of traditional medicinal importance, with various parts used to treat ailments like snakebites, stomach complaints, and certain types of pain and swelling.
Name in Different Countries
Scientific Name: Thunbergia grandiflora (Roxb. ex Rottl.) Roxb. Common English Names: Bengal Clock Vine, Bengal Trumpet Vine, Blue Sky Flower, Blue Sky Vine, Blue Trumpet Vine, Clock Vine, Skyflower, Skyvine. Nepali (from Hindi/Bengali): नील लत्ता (Neel lata). Assamese: Kukua loti Bengali: নীল লতা (Neel lota) Chinese: 大花山牵牛 (Dà huā shān qiān niú), 大花老鸦嘴 (Dà huā lǎo yā zuǐ) Gujarati: Tumakhlung Hindi: नील लता (Neel lata) Khasi: Jermi khnong, Syntiew jyrni chankhlaw Malay: patok tuwauh Mizo: Vakohrui, Zawngafian, Vako Thai: สร้อยอินทนิล (S̄r̂xy xin thnin) Vietnamese: Dây bông xanh
Terminology
Family: Acanthaceae (A family of flowering plants, mostly tropical herbs, shrubs, or vines). Botanical Description: It is a woody vine (liana) that can reach 10-20 meters in length. Leaves: Opposite, large (15-26 cm long), ovate or broadly ovate, often with lobate-dentate (lobed and toothed) margins and a cordiform (heart-shaped) base. Flowers: Large, showy, trumpet-shaped (infundibuliform), with 5 lobes, typically lilac-blue or mauve with a pale yellow or whitish throat. They are borne in clusters (racemes) on drooping branches. Fruit: A capsule that is subglobose at the base with a long, pointed beak, dehiscent (splitting open) in two halves to explosively disperse the seeds. Synonyms (Botanical): Flemingia grandiflora Roxb. ex Rottl., Pleuremidis grandiflora (Roxb. ex Rottl.) Raf., Thunbergia adenophora W.W. Sm., Thunbergia chinensis Merr., Thunbergia cordifolia Nees, Thunbergia lacei Gamble.
Availability
Native Range: Central Nepal to Southern China and Peninsula Malaysia. Distribution: It grows primarily in the wet tropical biome. It is widely cultivated as an ornamental in tropical and subtropical regions globally and has become naturalized or invasive in many parts of the world, including parts of the USA, Central America, Africa, Australia, and various oceanic islands. Habitat in Native Regions: It is often found along riverbanks, in forests (especially margins and disturbed areas), open woodlands, and on roadsides and fence-lines. It thrives in well-drained, fertile soil in full sun or partial shade, and in frost-free areas. In Nepal: It is part of Nepal's flora, specifically noted to be native to Central Nepal, and is recognized as a useful plant for medicine and other uses.
External Look
Growth Habit: A very vigorous twining vine that can climb high, up to 15-20 meters, covering large structures like trellises, fences, or host trees. Stems: Younger stems are green and somewhat hairy (pubescent). Older, mature stems become thick, woody, brownish, and rounded. Leaves: They are large, bright or dark green, and somewhat heart-shaped (cordiform) or broadly ovate, with coarsely-toothed or lobed margins. They are arranged oppositely along the stem. Flowers: The most distinguishing feature. They are large, about 6-8 cm across, and trumpet-shaped. The color is typically a lovely lilac-blue, violet, or mauve, with a contrasting pale yellow or whitish throat. There are also white-flowered varieties. The flowers are borne in long, drooping clusters. Fruit/Seed: The fruit is a small, brown capsule (about 3 cm long) with a spherical base and a long, pointed beak, which ejects the seeds upon ripening.
Healing Properties
Traditional Indications: Historically and traditionally used for: Snakebite 🐍 (a highly significant use in many regions). Stomach complaints and indigestion. Skin diseases, cuts, sores, and furuncles (boils). Rheumatic arthralgia (joint pain due to rheumatism) and algomenorrhea (painful menstruation). Eye troubles and eye pain. Bioactive Compounds and Scientific Potential: Phytochemical studies have revealed the presence of important compounds, including alkaloids, flavonoids, glycosides, saponins, tannins, and phenolic compounds. These constituents are associated with several properties demonstrated in laboratory or animal studies, such as: Antioxidant (mitigating oxidative stress). Anti-inflammatory (reducing inflammation). Antimicrobial (antibacterial and antifungal). Anthelmintic (expelling parasitic worms). Potential anti-arthritic and anticancer properties.
Advantages
Multi-purpose Utility: Serves as an ornamental plant for its showy flowers, a functional vine for quickly covering fences/trellises, a soil stabilizer (erosion control), and a source of traditional medicine. Fast Growth and Vigor: It is a very robust and rapid grower, which is an advantage for quick coverage in gardening and landscaping. Rich Phytochemistry: The presence of compounds like flavonoids (quercetin, kaempferol) and phenolic acids supports its wide range of traditional medicinal uses and suggests significant therapeutic potential, especially as an antioxidant and anti-inflammatory agent. Ease of Cultivation: It is hardy and can adapt to various soil types, requiring low maintenance once established in suitable climates.
Uses
Traditional Medicine: Snakebite: Leaves are a highly reputed traditional remedy; the juice is often massaged into the bite site, and the residue applied as a poultice. Digestive Issues: Leaf decoction is drunk for stomach complaints and indigestion. Skin Ailments: Leaf paste is used as a poultice for skin diseases, cuts, sores, and furuncles. Pain/Inflammation: Used for rheumatic arthralgia, algomenorrhea, and swelling pains caused by falls or fractures. Eye Care: Sap from the stem may be used to treat eye troubles/pain. Horticultural/Ornamental: Extensively grown as an ornamental climber for its beautiful, large blue or white flowers to cover arbors, pergolas, trellises, and fences. Ecological: Used for erosion control due to its robust growth and fibrous root system, and it also attracts pollinators.
Using Way
Traditional preparation methods vary depending on the ailment and the plant part used: For Snakebites/Cuts/Sores: Poultice/Paste: Fresh leaves are pounded or crushed to extract the juice, which is then used to massage the affected area, and the remaining pulp/residue is applied externally as a poultice. Dried, powdered leaves can also be moistened and applied. For Stomach Complaints and Indigestion: Decoction: A decoction (tea) made by boiling the leaves in water is prepared and drunk. For Eye Troubles: Sap: The watery sap from the stem is sometimes collected and diluted or applied carefully to the eyes. For Rheumatic Pain/Swelling (Internal): Decoction: A decoction of the roots (15-30g) is taken orally. For Rheumatic Pain/Swelling (External): Wash/Poultice: Fresh roots or stem leaves are smashed for applying externally or decocted for washing the affected parts. Important Note: As with any herbal medicine, preparations should be made under expert guidance, and modern medical attention should always be sought, especially for serious conditions like snakebites.
Conclusion
Thunbergia grandiflora is a highly vigorous, beautiful flowering vine native to South and Southeast Asia, including Nepal. Its common name, Neel lata, points to its distinctive blue/lilac flowers. The plant holds significant value in traditional medicine, particularly for its widely recognized use as an antidote for snakebite, as well as for treating stomach, skin, and inflammatory conditions. Its efficacy is attributed to a rich profile of bioactive compounds exhibiting antioxidant and anti-inflammatory properties. While celebrated ornamentally for its rapid growth and showy flowers, its therapeutic potential continues to be a subject of pharmacological research, confirming its status as a versatile and important medicinal plant.
