Snowdrops herald spring's approach
THE snowdrop is one of the early-flowering plants that heralds the welcome approach of springtime. The dainty little herb has remarkably bright flowers that are whiter than snow and, as the plant's name tells us, each solitary flower drops to hang upside-down.
Snowdrops are native to southern Europe. In Ireland the Snowdrop is a garden escape and while it has naturalised itself over large areas of Europe it is rare here. It was once believed that the species might be native to Britain but the weight of expert opinion now favours the idea that it is a long-established alien that was possibly introduced from their homeland by Romans invaders.
A member of the large Lily family, Snowdrop flowers are rich in nectar and are an important food source for early-flying insects such as hungry queen bumblebees emerging from hibernation and eager for a quick intake of sugar.
Flower parts evolved from modified leaves and are arranged in rings called whorls. The outermost whorl of flower parts is called the perianth. In shape the perianth can be pictured like a bowl surrounding the outside of the flower and enclosing all of its inner parts. In structure the perianth is composed of a number of leaf-like segments arranged in two layers: an inner layer and an outer layer.
Sometimes the two layers of perianth segments look exactly the same. Sometimes they look totally different. And, to confuse matters, there are several intermediate arrangements between these two extremes.
Take a Tulip for example. The perianth is made up of six segments, three inner ones and three outer ones. They are all brightly coloured, all have the same shape and all therefore look the same. These undifferentiated perianth segments are referred to as tepals.
Now take a Rose bud. The segments of the perianth are clearly differentiated into two totally different kinds: five outer sepals that are green and look like leaves and a number of inner brightly coloured petals that are often sweetly scented.
Snowdrops fall in between these two extremes. Like the Tulip, the perianth of each flower is composed of six segments but they are neither identical as in the case of the Tulip nor totally different as in the Rose bud. The three outer Snowdrop perianth segments are large, are curved inwards and are pure white. The three inner ones are shorter and are notched, each notch surmounted by a green mark shaped like a hump-back bridge.