Plant 188

Drimys winteri J.R.Forst. & G.Forst. (Winteraceae)

Winter's bark

The genus Drimys comprises approximately eight Central and South America species that are distributed from Mexico to Tierra del Fuego. One species (Drimys confertifolia) is endemic to Juan Fernandez Islands. Of these species, only Drimys winteri is well known in cultivation. A species that has proven its horticultural worth as a foliage and flowering plant for nearly two centuries, since its introduction in 1827.

Drimys winteri is an Andean species of Chile and western Argentina. It varies in habit from a small shrub to a tree reaching twenty metres in height. Individual trees have a conical form with fawn-brown to greyish, highly aromatic bark. The aromatic, evergreen, spear-shaped leaves have smooth margins and are often blue-green on their lower surfaces. Individual, stalked flowers are arranged in clusters. Each ivory-white flower may be up to four centimetres in diameter, with variable numbers of petals ranging from four to twenty. The numerous stamens surround four or more free carpels, which mature to form fleshy berries that are probably dispersed by birds.

Until recently, the genus Drimys included southern hemisphere species whose native ranges extend from Australia to the Philippines. However, floral morphology and DNA sequence evidence show Drimys is restricted to the Americas; the Australasian species are in the genus Tasmannia. This is not the first time the taxonomy of Drimys has changed; it used to be in the magnolia family (Magnoliaceae). The Magnoliaceae and Winteraceae are readily separated. The latter do not have stipules associated with their leaves and have small flowers with carpels arranged in a single ring; in Magnoliaceae carpels are arranged in spirals.

When Francis Drake sailed around the world in the Golden Hind and rounded Cape Horn, of the four ships in his flotilla, the only one that successfully accompanied him was the Elizabeth, captained by John Wynter. However, a storm separated the two ships and Wynter turned back. Presumably due to sickness on board Wynter's ship, a boat was sent ashore to search for medicines. It returned with a supply of Drimys bark and for centuries before vitamin C was isolated, Winter's bark was recognised as a preventive and cure for scurvy.

In the majority of flowering plants, the water-conducting cells in stems comprise two cell types; vessels and tracheids. Vessels are wide tubes with thin walls; tracheids are narrow tubes with thick walls. Drimys winteri is one of the few species that only have tracheids.

Further reading

Bean WJ 1973. Trees and shrubs hardy in the British Isles. Vol. 2. John Murray.

Clennett C 2004. The southern hemisphere garden at Wakehurst Place. Curtis's Botanical Magazine 21: 81-87.

Doust AN and Drinnan AN 2004. Floral development and molecular phylogeny support the generic status of Tasmannia (Winteraceae). American Journal of Botany 91: 321-331.

Ben Jones