Once upon a time, the sight of a yellow or bright pink flower in the showcase beds around the All England Club would have merited a dress code violation, but the emphasis on the theme of an English Country Garden means that Head Gardener Martyn Falconer has had the freedom to add some pastel splashes to the traditional palette of purple and white blooms.

Enter the foxglove, also known as digitalis. There are 550 examples of this quintessential cottage garden flower to be found around the grounds, planted as if they have just popped up naturally as they do in the wild. The flowers are produced on a tall spike and come in a range of soft creamy yellows, pale and deep pinks and vibrant purple. Some also possess various marks and spotting.

“They grow to a height of two to three feet, and we have introduced them with lupins in the last few years to soften up the look,” says Martyn.

But the species has lethal properties. Most of us have grown up with warnings not to touch the plant, which is common both in the garden and in the wild. All parts are poisonous, including the roots and seeds. Its extreme toxicity gives it the potential to kill in small amounts. As such it features as a murder weapon in myriad television dramas and in crime literature. Agatha Christie chose it as the fatal instrument in Appointment with Death and the American best-selling thriller writer Elizabeth Peters employed it in Die For Love. It has been the weapon of choice in various episodes of CSI, Colombo and Murder She Wrote.

The toxicity is due to the presence of digitoxin - a compound which disrupts the function of the heart. Conversely, digitoxin is also the source of medication that can regulate the pulse and has saved hundreds of thousands of lives since its discovery in 1775. An old saying about foxglove goes: "It can raise the dead and it can kill the living.”