Cestrum diurnum is a species of Cestrum, native to the West Indies. Common names include day-blooming cestrum, day-blooming jessamine, and day-blooming jasmine. Also known as Din ka Raja (king of the day), in Urdu and Hindi. The scent of this quick-growing and evergreen woody shrub, often used for screens and borders, is released by day. Cestrum diurnum is easily propagated from the seed, which it produces in abundance.[1]
It is an erect evergreen woody shrub with numerous leafy branches. The branches, which are green and with well-marked white lenticels when young, fawn with age. The younger parts are covered with a very sparse glandular scruf.[1]
The leaves are simple, glabrous, entire, alternate, ex-stipulate, ovate-lanceolate in shape with obtuse apex and obtusely wedge-shaped below. They are dark green above and pale below and are generally 5 inches long by 1.5 inches wide. The leaves are petiolate with petioles of 0.5 inch length.[1]
The Inflorescence consists of a long axillary peduncle which bears short clusters of sweet white-smelling flowers, each cluster supported by a leaf-like bract. The individual flowers are sessile and may be with or without bracteoles.[1]
Calyx is gamo-sepalous, about 0.15 in long, somewhat puberulent, obtusely 5-ribbed and 5-lobed with obtuse, ciliate lobes.[1]
Corolla tube is narrowly infundibuliform, white, sweet-scented, about half-inch lobed with five lobes. The lobes are very obtuse and completely recurved when the flower is fully open.[1]
Stamens oblong, five in number, alternate with the corolla lobes, brown in colour, included. Filaments adnate to the tube, free for a very short distance.[1]
Ovary seated on a nectar-secreting disk. The style is filiform and glabrous. The stigmas are truncate-capitate.[1]
Cestrum diurnum has a black, nearly globular berry.[1]
A native of the West Indies, it is widely cultivated in gardens throughout India.[1]
Leaves of Cestrum diurnum are reported as a sources of vitamin D3.[2] Aerial parts are also reported to have cytotoxic and thrombolytic activities.[3]
Cestrum diurnum is one of only three rangeland plants known to contain glycosides of the vitamin D metabolite 1,25-dihydroxycholecalciferol aka 1,25-OHD3. Consumption of glycosides of 1,25-OHD3 by grazing animals leads to a vitamin D toxicity resulting in calcinosis, the deposition of excessive calcium in soft tissues.[4]