Climbing Oleander

This genus of 38 species of evergreen or deciduous shrubs, climbers, and small trees occur in tropical Africa and Eurasia. Several species were cultivated under glass in the 19th century for their interesting flowers, which have long, ribbon-like petals. A few are occasionally seen today in botanical gardens. Strophanthus gratus contains cardiac glycosides, including ouabain, and strophanthin; the latter was first isolated in 1885. These compounds are poorly absorbed when taken orally and are usually given by injection. Unlike digitalis (See Digitalis, Woolly Foxglove), they are not cumulative. Similar glycosides are found in S. hispidis, S. intermedius, and S. kombe. Locally, these plants are used in the preparation of arrow and fish poisons. The seeds are soaked in water to obtain a highly toxic liquid that is mixed with adhesive and applied to the tips of weapons. The effects of S. kombe were noted by David Livingstone, the explorer, in 1861. Strophanthus is from the Greek strophus, "twisted cord", and anthos, "flower" referring to the twisted petals.

Robust, evergreen climber with purple-stalked, leathery, oblong-elliptic, pointed leaves, to 18cm (7in) long. Purple buds expand into night-scented, bell-shaped flowers, 6cm (2½in) across, which are purple-pink outside and white to pink inside, with 5 pairs of purple appendages. Forked fruits, to 40cm (16in) long, containing green-brown seeds with long silky plumes, develop over 12 months.

Common Name:	Climbing Oleander
Other Names:	Smooth Strophanthus, Sawai
Botanical Name:	Strophanus gratus syn. Roupellia grata
Genus:	Strophanus
Family:	Loganaceae
Native Location:	W Africa
Cultivation:	Moist, well-drained, rich soil in sun, with high humidity.
Propagation:	By seed sown when ripe; by ripewood cutting in early spring. Plants take 3 years to reach flowering size when grown from seed; maximum fruit production occurs after 6-10 years. Many flowers fo not set seeds.
Harvest:	Seeds are collected when ripe and processed commercially for the extraction of glycosides.
Height:	9m (28ft)
Hardiness:	Min. 16°C (61°F)
Parts Used:	Seeds
Properties:	An extremely poisonous, diuretic, tonic herb that stimulates the heart.
Medicinal Uses:	Internally, usually by injection, for heart failure, angina, hypertension, pulmonary edema, and hypotension during anesthesia and surgery.
Warning:	Seeds are extremely toxic if eaten. Excess causes cardiac arrest. For use by qualified practitioners only. This herb is subject to legal restrictions in many countries.
Bibliography:	Encylopedia of Herbs by Deni Brown Copyright ©: 1995, 2001 Dorling Kindersley Limited pg 376