Convolvulus prostratus Seeds | Prostrate Bindweed
LATIN NAME: Convolvulus prostratus
COMMON NAME: Prostrate Bindweed
Plant Profile
Prostrate bindweed is a plant that keeps its head down. The stems radiate from a woody rootstock and lie along the ground, sometimes rooting where they touch, and the whole mat rarely stands more than a hand’s height. The leaves are small, narrow and grey-green, and the flowers are the reason anyone grows it: funnel-shaped, two centimetres across, white with a pink flush and a yellow eye, opening in the morning and closing by afternoon. It grows on dry stony slopes and sandy flats from north-west India and Pakistan through Iran and Arabia to the Horn of Africa, and it flowers through the hottest months when most of its neighbours have finished. In Ayurvedic practice it is one of the plants called shankhpushpi, a name that has been applied to at least four different species.
Science & Biotechnology
The identity of shankhpushpi is one of the more instructive muddles in Indian materia medica. Convolvulus prostratus — often treated as synonymous with C. pluricaulis — is the source in much of northern and western India, while Clitoria ternatea and Evolvulus alsinoides are sold under the same name elsewhere, and the three have different chemistry and different clinical literature. Work on C. prostratus itself has focused on the whole-plant extract, reporting scopoletin, catechin and kaempferol derivatives, and a series of small animal studies describing improved retention in maze tasks and reduced anxiety-like behaviour. The studies are small, the extracts are not standardised, and the species used is not always verified, which is why the pharmacology remains suggestive rather than settled. The plant is a Convolvulus, and the genus is not one of the tropane-alkaloid bindweeds, so it does not carry the toxicity of the Datura relatives.
Uses & Benefits
Its traditional role is as a nerve tonic and a memory aid, taken as a powder or a decoction of the whole dried plant, usually with ghee or milk; it is one of the medhya rasayana of Ayurveda, herbs given to students and to the elderly. Anyone buying it should insist on a botanical identity, because the name alone guarantees nothing. In the garden the plant is a useful groundcover for a hot, dry, poor bank — it knits the surface, holds light soil through the monsoon, and flowers for months on end with no irrigation once established. The flowers are visited by small bees and by hawk moths at dusk, and the mat is dense enough to suppress annual weeds. It is not a plant for rich soil or for shade, where it grows soft, open and flowerless.
Growing from Seed
The seed coat is hard and the seed is small, so the simplest approach is to soak it for a day in warm water and sow it on the surface of a sandy compost, pressed in but barely covered. Keep the tray at 20 to 25 °C in full light and water from below; germination takes ten days to three weeks and is usually good. Prick the seedlings out early, because they resent root disturbance once the taproot has run, and pot them into deep containers. Plant out in full sun on poor, sharply drained ground and water only until the mat closes. The plant is drought-deciduous in extreme conditions and will return from the rootstock after rain. A light shear after the first flush keeps the mat tight and encourages a second run of flowers.
Our Take
A modest mat-forming perennial with a long medicinal reputation and a tangled one; grow it for the flowers and buy the herb by Latin name.
Related Reading
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