Perennial herbs, climbing shrubs, or twiners.
Tap root system.
Herbaceous, woody, erect, twiner, climbers, cylindrical, generally pubescent, branched and solid.
Opposite, decussate, exstipulate, shortly petioled, simple, generally pubescent, margin entire, unicostate reticulate venation. Leaves reduced to spines in Stapelia.
Generally cymose and occassionally a raceme, Axillary cyme in Hemidesmus. Terminal or axillary cyme in Periploca, umellate cyme in calotropis and Gymnema. Umbellate or corymbose cyme in Marsdenia.
Pedicellate, bracteate, hermaphordite, actinomorphic, hypogynous, complete.
Sepals 5, polysepalous, or united near the base, quincuncial aestivation.
Petals 5, gamopetalous, aestivation contorted or valvate, corona generally present.
Stamens 5, polyandrous, stamens & stigmatic head adhere together to form pentagonal gynostigium. The pollen grains of each half anthers are united together in a structure called pollinium. Each pollinium has a translator by means of which the pollinia of two adjacent anther halves are united. Translator has corpusculum which is gland like and a pair of retinaculi or the connectives.
Bicarpellary, ovary superior. Apocarpous because the ovaries are invariably separate. Each ovary is unilocular with marginal placentation. Styles two at the base but finally become one. The style finally ends in pentogonal stigmatic head.
An aggregate fruit in the form of etaerio of follicles.
Asclepias are the most ornamental plants of the family. Periploca flowers are eaten. Its stem yields fibre which is used in making ropes. Its latex is also medicinally important. Gymnema sylvestre (Gurmar) in a pubsescent climbing shrub. Its leaves contain gymnemic acid and when chewed, temporarily destroy the sense of tasting sweets.
Marsdenia is also a twinning shrub and its stem yields a very strong fibre. Cryptostegia grandiflora is a climbing shrub with beautiful rose coloured flowers. It is cultivated for its ornamental value. It is ever green and an extreme xerophyte.