In a charming if botanically fanciful sentence, the Roman naturalist Pliny wrote that the common convolvulus, that white trumpet-flower that tramps over hedgerows with unkempt abandon, is ''a rough sketch which Nature made when learning to produce the lily.''
It is a comment that not only aptly catches the rather careless, untidy character of the convolvulus and its short-lived flowers, but at the same time indicates an admiring attitude towards the lily and its particularly satisfying form. Pliny clearly thought of it as an ideal, perfected kind of flower.
Anciently cultivated, the lily - in this case Lilium candidum - was a great favourite in Roman gardens, second only to the rose. Indeed, the Romans took the lily and grew it all over their empire. The white brilliance of its petals, which curve back to reveal orange-yellow stamens heavy with pollen, is seen in summer. It must be this purity which came to be associated with the Annunciation. Season has little to do with it, because the religious event is traditionally celebrated in March, when Lilium candidum is still dormant in the earth in northern climes. In Italian and Flemish paintings of the Middle Ages and Renaissance, the angel Gabriel, announcing the good news to Mary, is often depicted bearing a lily stalk. Sometimes a lily is nearby in a vase. Either way, its presence was usual, and its significance understood. From this association is derived Lilium candidum's popular name, the ''Madonna lily.''
There is an air of finality about the lily, as if other flowers might almost be evolutionary stages towards the development of its completeness. The large number of flowers loosely and popularly known as ''lilies,'' in spite of having no relation to the Lilium at all, also points to this flower as quintessential. It is sturdy, vigorous, as definite in bud as it is firm in the flower, not too lush and juicy, not overblown, by no means flimsy: yet, for all these solid virtues, it is never stiff or starchy, and has a sun-loving delicacy of visage and a freshness that no artificial imitation could remotely capture.
The Madonna lily manages symbolically to combine the luxurious with the chaste. Its suggestion of distinction - even rarity - is happily belied by the ease with which it flourishes in neglected cottage gardens and the difficulties it presents to horticulturists with show gardens who fuss and fret and disturb it with attention. Inhabiting a small back garden, forgotten in a corner until it startles the eye with loveliness, its trumpets blaring in all directions, this summer flower seems both exotic and natural.
In Leonardo's painting of the Annunciation, in the Uffizi in Florence, the angel carries a lily stalk. The drawing shown here, from Windsor, is in an early style that suggests to scholars that it ought to be the cartoon (pricked as it is for transfer to a painting panel) for the Uffizi picture. But it fails to correspond in a number of details, not the least of them being that it leans to the left as if its angel would be carrying it over his shoulder. A painting in the National Gallery, London - a ''Madonna'' from the workshop of Verrocchio (Leonardo's master) - contains a lily much closer to this fine drawing. However, it is still not identical. So the drawing's precise use is unknown.
That it represents a practical stage in the production of a painting there can be little doubt, and it is an unusual survival in this respect: although most of the Florentine genius's early works contain prominent details of vegetation, and though he records in writing that he made many studies of flowers from nature, none of these early drawings of plants are known today. Flowers also appear often in paintings by his contemporaries. But it was apparently not the custom to preserve the evidence of preparation for such details. The beautiful lily is an exception.
Kenneth Clarke describes it as being ''in a style quite unlike that of Leonardo's other botanical studies,'' and another scholar has pointed out its slow contour line and its unusual combination (for Leonardo) of pen, ink, and wash over black chalk. For all its uniqueness, though, nobody seriously doubts its authenticity. As an observation and appreciation of the lily it has become a justly famous and favourite drawing.