Plant familes: Solanaceae

All plants in the Solanaceae family have alternate leaves and colorless sap. They have perfect (bisexual) flowers, typically with five fused petals. The most well-known genera include Lycopersicon (tomato), Capsicum (peppers and chillies), Physalis (tomatillo) and Solanum (potato and aubergine). Less common genera include Atropa (deadly nightshade, also known as belladonna), Petunia (petunia) and Nicotiana (tobacco).

Many Solanaceae species have all or some parts which contain alkaloids and are therefore narcotic. In small quantities they depress the nervous system and may be used for their analgesic properties. But in large doses, they can be fatal. Some can cause hallucinations, including deadly nightshade (Atropa belladona), Brugmansia, hen bane (Hyoscyamus) and mandrake (Mandragora). The name Atropa belladonna ('beautiful lady') is thought to relate to the practise of Italian women, who used its sap in eyedrops to make their pupils dilate.

Even edible plants in the Solanaceae family can cause problems: the leaves and stems of tomatoes, aubergines, peppers and potatoes contain small quantities of the alkaloid solanine. However, if exposed to light, potato tubers can develop high concentrations of this poison (identified as 'green potatoes'), which can cause stomach upset and even death.

The name Atropa belladonna ('beautiful lady') is thought to relate to the practise of Italian women, who used its sap in eyedrops to make their pupils dilate.

We take a look at some popular members of the Solanaceae family, below.

Brugmansia

Known an angel’s trumpet, Brugmansia is an evergreen shrub native to the tropical regions of Brazil. In the UK it's typically grown in containers in the conservatory or greenhouse. It has large, trumpet-shaped flowers in white, cream, pink, yellow or orange. Having evolved to be polliated by bats and moths, its blooms emit a stronger fragrance in the evening. Although not fully hardy, container-grown plants can be moved on to a sunny patio for the summer.

H x S: 250 x 250cm

Cestrum

Cestrum is a genus of flowering plants native to temperate and tropical regions of the Americas. They're commonly known as cestrums or jessamines, due to their fragrant flowers (like jasmines). Mostly evergreen, in the UK they are typically grown in containers in the conservatory or greenhouse. All parts of the plants are toxic, causing severe stomach upset if eaten.

H x S: 250 x 150cm

Petunia

Native to South America, petunias get their name from the French ‘petun’, meaning ‘tobacco’, owing to its close resemblance to closely related tobacco plants. An annual, most of the varieties we grow in our gardens are hybrids, known as Petunia × hybrida. Bearing large, bright flowers over a long period, petunias are a popular bedding plant, and the trailing habit of some cultivars makes them perfect for hanging basket or container displays. Fast growing and requiring very little maintenance, they come in a range of bright colours and flower shapes.

H x S: 50 x 100cm

Nicotiana

There are many species in the Nicotiana family, most notably Nicotiana tabacum, which is used in the production of cigarettes. Most plants hail from the Americas, Australia, south west Africa and the South Pacific. Some species are grown as ornamental garden plants. Pollinated by moths in its native habitat, Nicotiana sylvestris is more commonly used as bedding in the UK but its flower tubes are too long for British pollinators. Nicotiana alata (pictured) has greater wildlife value as its flower tubes are shorter and more well suited to the tongues of our native species.

H x S: 60 x 30cm

Solanum crispum

The Chilean potato vine, Solanum crispum, has wiry stems, clad in small semi-evergreen leaves which remain on the plant in all but bad winters. The potato-like flowers, each with lilac petals around a pointed yellow centre, appear continuously from mid-summer to mid-autumn. Solanum crispum 'Glasnevin' (pictured) flowers more prolifically, and is hardier than other species. The Royal Horticultural Society has given it its prestigious Award of Garden Merit (AGM).

H x S: 600 x 400cm

Solanum laxum

The potato vine Solanum laxum has slightly fragrant, white flowers, each with a central pointed yellow centre, from mid to late summer. Like its relative Solanum crispum, its wiry stems need tying to wires or trellis for support, but its small, semi-evergreen leaves are thinner and more delicate-looking, and it's far less hardy. The Royal Horticultural Society has given it its prestigious Award of Garden Merit (AGM).

H x S: 600 x 180cm

Solanum melongena

Also known as eggplant, due to the shape of the fruit of earlier varieties, aubergines are becoming an increasingly popular choice for the kitchen garden. The botanical name 'melongena' relates to the Italian 'melanzane', meaning 'mad apple'. Given a good summer, plants can be very productive, especially when grown under glass. However, aubergines are sensitive to cold and rain, making them less reliable in our British climate.

H x S: 90 x 60cm

Capsicum annuum

Capsicum annuum is native to the Americas. Despite its name, it’s actually a perennial, although it's best treated as an annual in our British climate. Cultivated for many years, it’s been bred to five common types of pepper: sweet, or bell peppers, jalapeños, paprika, chilli, and cayenne peppers. Depending on the cultivar, the ‘peppers’ ripen to red, orange, yellow, brown or even brown-black, and can be sweet or hot.

H x S: 90 x 30cm

Lycopersicon esculentum

Native to South America, Lycopersicon esculentum bears the common tomato fruit. It was first brought to Europe by the Spanish, during their colonisation of the Americas during the 16th Century. The name ‘tomato’ derives from the Aztec ‘tomatl’ and the Spanish ‘tomate’. There are many cultivars, yielding large and small, and differently coloured fruits.

H x S: 150 x 60cm

Solanum tuberosum

We use Solanum tuberosum for its starchy, tuberous roots, or potatoes. Potatoes are the world's fourth-largest food crop, following maize, wheat, and rice. They were introduced to Europe in the 16th century by the Spanish. There are now over a thousand different types of potatoes.