[4] The surface of the plant is covered in a mix of chemicals including psoralen, xanthotoxin and bergapten[citation needed] that causes a phototoxic reaction resulting in blistering two or three days after exposure.

Exposure of the affected skin to ultraviolet light, such as contained in sunlight, triggers the effects of the plant's toxins, leading to severe itching and blistering.

The welts and resulting blisters can be as small as the size of a coin to covering as much exposed skin as came into contact with the plant.

Direct application of the spray-on types of sunscreen, particularly those high in alcohol, tends to both dry the welt and reduce the irritation with immediate effect.

In the traditional medicine of the indigenous peoples of the Cape, it has been recorded as a diuretic and as a treatment for rheumatism, gout, bladder ailments, water retention and high blood pressure.

When cultivated, it prefers a relatively sunny position, but tolerates a mildly shady or moist spot provided that this is coupled with well-drained soil.