Erect to spreading tree 2-4m (6-12ft) high by 1.5-3m (5-10ft) wide, producing pinnate, yellow-green leaves, 40-90cm (16-36in) long, with 6-8 oblong-lanceolate shaped leaflets. Axillary corymbs, 10cm (4inch) across, to up to 20 golden yellow flowers, to 2cm (3/4in) across, are borne in late summer.

The source of one of the best known of all herbal medicines – senokot (and senna pods and senna tea), introduced to European medicine (as Senna alexandrina from Egypt) by the Arabians. Every part of the plant contains anthraquinones which, if taken internally, act as a powerful laxative to treat constipation by stimulating the nerve cells of the large bowel. Gerard (1633) notes ‘it is a singular purging medicine’ with over a page on its uses. When used regularly the nerves to the large bowel may be destroyed, leaving a permanently dilated large bowel that never functions properly again. This is a plant which causes the condition it treats to become permanent. Additionally, with prolonged use, the lining of the bowel turns black, serum potassium levels may fall, resulting in cardiac irregularities and sometimes death. Coma, neuropathy and hepatitis have also been reported. It is advertised on television (the actor involved is seen to be depressed and bloated until she takes Senokot, after which she is happy - Hippocrates would have attributed this antidepressant effect to the plant's ability to purge her of the black melancholic humour present in her bowel motions). It is available without prescription or health warning against long-term use. What do you think? Lyte (1578) recommends it strongly for depression, but one might claim to be cured rather than take it again.

Medicinal uses Uses supported by clinical data Short-term use in occasional constipation (21–25). Uses described in pharmacopoeias and in traditional systems of medicine None. Uses described in folk medicine, not supported by experimental or clinical data As an expectorant, a wound dressing, an antidysenteric, and a carminative agent; and for the treatment of gonorrhoea, skin diseases, dyspepsia, fever, and haemorrhoids (11, 23, 25).Medicinal uses Uses supported by clinical data Short-term use in occasional constipation (21–25). Uses described in pharmacopoeias and in traditional systems of medicine None. Uses described in folk medicine, not supported by experimental or clinical data As an expectorant, a wound dressing, an antidysenteric, and a carminative agent; and for the treatment of gonorrhoea, skin diseases, dyspepsia, fever, and haemorrhoids (11, 23, 25).Medicinal uses Uses supported by clinical data Short-term use in occasional constipation (21–25). Uses described in pharmacopoeias and in traditional systems of medicine None. Uses described in folk medicine, not supported by experimental or clinical data As an expectorant, a wound dressing, an antidysenteric, and a carminative agent; and for the treatment of gonorrhoea, skin diseases, dyspepsia, fever, and haemorrhoids (11, 23, 25). Contraindications As with other stimulant laxatives, the drug is contraindicated in persons with ileus, intestinal obstruction, and stenosis, atony, undiagnosed abdominal symptoms, infl ammatory colonopathies, appendicitis, abdominal pains of unknown cause, severe dehydration states with water and electrolyte depletion, or chronic constipation (21, 30). Folium Sennae should not be used in children under the age of 10 years.

It has Traditional Herbal Medicine Registration approval in the UK

There is a video by Dr Henry Oakeley

There is a Podcast by Prof Anthony Dayan

Text of a podcast by Prof Anthony Dayan

syn. Cassia corymbosa

video on Senna by Henry Oakeley

When used regularly the nerves to the large bowel may be destroyed, leaving a permanently dilated large bowel that never functions properly again. This is a plant which causes the condition it treats to become permanent. Additionally, with prolonged use, the lining of the bowel turns black, serum potassium levels may fall, resulting in cardiac irregularities and sometimes death. Coma, neuropathy and hepatitis have also been reported.