Wild Senna



This genus of about 260 species of perennials, shrubs, and trees occurs mainly in the tropics and subtropics. It is often included in Cassia. A few species are grown as ornamentals in warm regions or in greenhouses in temperate regions. Senna marilandica is one of the hardiest, but needs a sheltered situation outdoors in cold areas. The roots were used as a laxative by the Cherokee, and also to relieve fever, cramps, and heart problems. The use of S. alexandrina as a laxative was introduced to Europe by Arab physicians in the 9th and 10th centuries. Senna alexandrina is the main ingredient of most laxative preparations, but various other species also contain laxative anthraquinone glycosides (sennosides). The pods of S. fistula (pudding pipe tree) are up to 50cm (20in) long and contain a black pulp, which is used as a mild for S. alexandrina. Sennas are useful for a wide range of other complaints, ranging from ringworm (S. alata, S. obtusifolia, and S. sophera) to venereal disease (S. sieberiana and S. surattensis). Senna reticulata yields the antibiotic Rhein-cassic acid, which is effective against various bacterial and fungal infections. Senna obtusifolia (Sickle senna) was recorded in Chinese medicine druing the later Han dynasty (CE25-220). It is used in patent medicines and to treat hypertension, high cholesterol leves, constipation, skin diseases, and eye disorders. The seeds of S. laevigata, S. obtusifolia, S. occidentalis, and S. sericea are used as a coffee substitute in various parts of the world.

Perennial with erect to sprawling stems and dull yellow-green, pinnate leaves, to 28cm (11in) long, divided into 5-9 pairs of tapering, elliptic leaflets. Yellow flowers appear in racemes in summer, followed by stiff, hairy pods, to 11cm (4½in) long.


Common Name:
Wild Senna
Botanical Name:
Senna marilandica
Genus:
Senna
Family Name:
Caesalpiniaceae
Native Location:
Midwest and SE USA
Cultivation:
Well-drained soil in sun. Senna marilandica needs rich, moist, sandy oil. Pot-grown plants may be damaged by root mealy-bugs.
Propagation:
By seed sown in spring at 18-24°C (64-75°F); by semi-ripe cuttings in summer. Prune to shape and remove dead or badly placed growths in early spring.
Harvest:
Leaves are picked before and during flowering; pods are collected in autumn when ripe. Both are dried for use in infusions, powders, tablets, and tinctures.
Height:
60cm-2m (2-6ft)
Width:
15cm-1.2m (6in-4ft)
Hardiness:
Z3-9
Parts Used:
Leaves, pods.
Properties:
A laxative herb with a milder, slower effect than S. alexandrina.
Medicinal Uses:
Internally for constipation.
Bibliography:
Encyclopedia of Herbs ~ Deni Bown ~ Copyright © 1995, 2001, Doring Kindersley Limited ~ pp. 366-367