The delicately shaped flowers of bittersweet, lightly washed with purple but more boldly splashed with golden yellow, are suggestive of a broader family tree that includes both tomato and potato. The scientific name of Solanum links bittersweet with the other nightshades (placing it within the family Solonaceae) and with them it shares its inviting, though poisonous, fruits. It is these fruits that alarm cautious parents, even though cases of poisoning among children are very rare.
I have heard this plant referred to as ‘deadly nightshade’ on more than one occasion, a case of mistaken identity. Deadly nightshade, Atropa belladonna, is a bushy perennial with smart green leaves and purple-brown flowers. Its glossy black berries, which are green initially, are formed in the centre of the flowers – like glossy marbles, each sitting within a five-pronged rosette of green. Bittersweet, which is also known as ‘woody nightshade’, is a rambling climber, its clusters of pea-sized, scarlet red berries starting out green before maturing in colour as they ripen. These berries are oval in shape and reminiscent of miniature plum tomatoes.
Bittersweet was a familiar childhood plant, appearing each year along a stretch of hedgerow near to the house, and I can recall the warnings from my mother not to touch the berries. As the name might suggest the berries are very bitter and this makes ingestion, accidental or otherwise, less likely. Because it is rather attractive, and because the fruits are popular with blackcaps, blackbirds and thrushes, it is a plant that I like to see in hedgerows and wildlife gardens. There is, however, a tendency for gardeners to remove it, particularly so in public gardens, fearing that some child might eat one of the fruits.
Bittersweet is one of the less poisonous members of the nightshade family but there has been some debate around the degree of toxicity to humans. It is known, for example, that toxicity varies with the stage of ripeness – ripe fruits are less toxic – but it is also thought that the levels of the toxins may vary between years, influenced by the growing conditions under which the fruit has developed. A cautious approach, rooted in educating children about possible risks, should also be a respectful one, leaving the plant to grow unmolested.