Pretty as a picture: The art of painting plants

I went on a pilgrimage this week to see A Young Daughter of the Picts, on show at the Royal Academy in London. It's an extraordinary little painting watercolour and gouache on parchment that shows a wooded landscape and in front of it, the girl standing chillily naked except for a necklace and a sword slung round her waist on a gilded chain. Tattooed all over her body are symmetrically arranged flowers: single and double peonies, hollyhocks, heartsease, double columbines, lilies, tazetta narcissus, cornflowers, rose campions and yellow horned poppies. Placed on her knees are splendidly anachronistic Iris susiana, with yellow tulips curving round the contours of her thighs.

No Pictish girl of course would have known anything about that particular iris. Or the tulips. Neither were seen in Europe until the middle of the 16th century when they first came in from Central Asia. But to Jacques le Moyne de Morgues, the artist who painted the picture round about 1585, these flowers were the ravishing new wonders of the age. Pictish women were in vogue too (there's a terrific watercolour same period by John White in the British Museum showing one tattooed in stars and stripes) and by using the girl's body to display them, de Morgues gives extra significance to the flowers.

He was born in Dieppe, a town famous for its cartographers and illuminators, and sailed as passage painter on Ren de Laudonnire's ill-fated expedition to Florida. In September 1565 Spaniards overran the colony the Huguenots established there, but de Morgues managed to escape and eventually got back to France. By about 1580 he had settled among other Huguenots in Blackfriars, London, where he produced La clef du champs (1586) a pattern book full of woodcut portraits of plants. Like his contemporary, the Flemish painter, Joris Hoefnagel, he occupied that shifting ground where illustrations of flowers plant portraits turned into something more like art.

Where did de Morgues see the flowers he painted? They are so perfect, he must have had them in front of him at some stage. He may have seen them in Flanders, before he ever came to England, because Huguenot plant lovers quickly made themselves masters of the art of growing these new treasures. But perhaps he saw them in James Garrett's garden at London Wall, within a short walk of Blackfriars. Garrett was an apothecary, a fellow Huguenot, and one of the first people in England to grow successfully the new wave of plants from Central Asia.

Surrounded by images of flowers, as we are now, it's difficult to imagine a time when there weren't any. But as soon as the first really good portraits of plants began to come out of Italy the Carrara Herbal made in Padua about 1390 is particularly gorgeous you see how some plants had a special attraction for artists. Grape vines were always favourites. So were iris. They still are. Wandering into the Scottish National Gallery of Modern Art in Edinburgh recently, the first thing I saw was a stunning watercolour of oncocyclus iris by Elizabeth Blackadder who a few years ago was appointed Her Majesty's Painter and Limner in Scotland. The title may be archaic. The painting is anything but. The papery sheaths from which her iris flowers emerge are so tactile, I reached out to feel them. Luckily I stopped before the uniformed guard marched me out of the gallery.

Both vines and iris feature in a new show by the artist Emma Tennant. The grapes she has painted are 'Muscat of Alexandria', a bunch picked from the vine house at Chatsworth with an elegant trail of foliage and tendrils curling over them. "A well-known and most delicious grape," noted William Hogg in his Fruit Manual of 1875, and there they hang, lusciously, in Tennant's watercolour. The catalogue notes are as engaging as the images themselves. On the subject of grapes, she quotes the Edwardian epicure, Edward Bunyard:

"A certain aroma of opulence still clings to a fine bunch of grapes, suggesting broad acres and snugly walled gardens where the grape house is reserved for the climax of the visitor's admiration. The door, of course, is locked, and the gardener opens it with an air unattainable by any mere growers of tomatoes. A long and tedious apprenticeship is the obvious price that had been paid for such a pregnant gesture."

Many of the subjects Tennant paints come from her own garden in the Borders: leeks, grape hyacinths, rhubarb, white martagon lily, wild strawberries. But wherever she goes, it seems she can't resist the siren call. In the show are artichokes bought from the Rialto market in Venice, a monster quince from Corfu, a mushroom from Langleeford in Northumberland, the blossom of a 'Pitmaston Duchess' pear growing in a greenhouse at Beaufront Castle, aubergines from Great Glemham in Suffolk, but also cherries from a local supermarket.

She's been gardening and painting, she says, since she was five. Only in the past 20 years, though, has she been able to settle more seriously to the task. "Eventually we punched through the side of a cowshed which then became my studio. It was a huge breakthrough for me. It made all the difference, not having to work on the kitchen table."

Talking about her work, she is refreshingly direct. There's none of the word-jiggery you get from those who make their living writing about art rather than doing it. "I think you just get fit for it," she says simply. "I start up in spring, when the hours of daylight begin to stretch out a bit. At that stage, although I absolutely love it, painting is also an effort. By the middle of June, I'm kind of fit and from then on to autumn I think I do some of my best work."

That explains too why the show, which is hung almost as a gardener's calendar, starting with spring flowers and vegetables such as fritillaries and rhubarb, ends with a blaze of delectable late-summer images: pears, rosehips and figs with Corfiot olives and a pomegranate as the final, gorgeous flourishes.

The RA exhibition, An American Passion for British Art: Paul Mellon's Legacy, runs to 27 January 2008 (0870 8488484). Emma Tennant's show, Fruit, Vegetables and a Few Flowers, runs 17-20 December at 54 The Gallery, Shepherd Market, London W1 (020-7491 7322). Prices range from 450-5,000