Sundews: drosera
Proving that there was some reason to this little series of insectivorous plants we come to sundews – drosera. Despite being relatively unfamiliar to most gardeners these little plants are found on every continent apart from Antarctica although there are only a handful of species from North America and from Europe and it is largely a Southern Hemisphere genus with half the species coming from Australia and many more from South Africa and South America, though not west of the Andes and they are absent from Equatorial regions. European species have that characteristic rosette formation but others can be almost scrambling plants and they can die back to a resting bulb in adverse conditions – either cold or drought.
Three species are found in the UK and Ireland: D. anglica, D. intermedia and D. rotundifolia as well as D. x obovata which is a hybrid of D. anglica and D. rotundifolia. They tend to be most abundant in the west of the countries where rainfall is high and they are plants of wet, nitrogen-poor soils, usually on raised peat bogs but also in peaty soils beside streams.
The photo above, which I hope is D. rotundifolia, was taken in Connemara last year a few metres from the turf cutting below. It was a dull, wet day and I am afraid I did not hang around long enough to check the species and the photo is not really good enough for close examination!
Droseras are easy to grow in a bright place either outdoors or in a cool greenhouse as long as they do not dry out. Droseras have a different method of catching the insects that supplement their diet to the pitcher plants and do make an effort to move to catch them. The leaves are covered in tentacles, each with a blob of sticky liquid at the end and these catch small insects. They are also sensitive to movement though and as soon as they are touched they curl inwards to press the prey onto shorter hairs that produce the digestive juices. In most cases the leaves also curl in around the prey.
Although D. rotundifolia is quite common where the habitat is suitable, the best for cultivation for beginners is D. capensis, from South Africa. It is easy to grow and has long leaves that make more of an impact and the flowers, held well above the leaves, are pink rather than the dull white blooms of the European species.
Although these are not as large or showy as the pitcher plants and do not have the visual excitement of venus fly traps they are easy to grow and make nice pot plants on a sunny windowsill in a cool room or an organic method of controlling whitefly and other pests in a cool greenhouse.
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