The Itching Bean (Upupu)
"Upupu", the itching bean, is the Kiswahili name für a tropical plant known in English under so many names as monkey tamarind, velvet bean, cowage, cowitch, lacuna bean, and Lyon bean.
Mucuna pruriens is the scientific name of a legume from the papilionaceous plants family common in Africa and tropical Asia. The undemanding plant grows on dry patches in every form of shrub. During the flowering period its beautiful white inflorescences are pollinated by long-tongued insects.
The two jars with ripe Upupu beans on display at the Missionsmuseum’s Afrika lobby originate from the East African bush. The origin of the older jar with beans turned brown in the course of 100 years or more is uncertain.
The fresh beans in the other glass container were picked by the Museum director in August, 2019 near Ndanda Abbey. One must take greatest care while picking the beans. A slight vibration and even a light gust of wind triggers the plant to shed its fine hairs. These particulates penetrate the clothing and cause long lasting itching on the skin. Even taking a few showers cannot eliminate the "itching powder"; only rubbing down the skin with sand helps a little.
For botanical interested travellers in Africa the old rule in the Tropics applies to the appealing fruits – never touch anything you don’t know.
In an unripe state the plant serves as cattle feed for ruminants. It is best used in dried state as hay or silage because the plant is indigestive; even not all ruminant herbivores can tolerate it.
Humans can only eat the unripe pods and leaves of the plant after prolonged cooking; this is common in some parts of Africa. The plant is said to have an aphrodisiac effect. The dry Mucuna beans have an uplifting effect and serve ground as a coffee substitute. However, breaking the pods to get the beans causes the above mentioned effects.
There are cultured breeds of Mucuna with pods that no longer shed hairs or have non-allergic hairs. There are indications that Mucuna is pharmacologically active. The extract seems to increase dopamine secretion in the brain. For this reason the Upupu is discussed as a cure for Parkinson’s desease.
