January 23, 2010
January 23 - Rafflesia arnoldii
Plants can be parasitic, too and some of the best known are in the genus Rafflesia. These really unusual plants don’t have stems or leaves or even proper roots. Instead, they have structures known as haustoria, which penetrate the cells of their hosts, Tetrastigma vines, and steal their nutrients and water. The only part of the plant that ever is visible is the flower – and it’s a doozy! The flowers of Rafflesia arnoldii can be almost a meter in diameter, making them the largest in the world. And if the size wasn’t enough to get it noticed, it also has a very distinctive smell – like rotting flesh - that attracts the insects that pollinate it. Despite these factors, Rafflesia is very hard to find. Part of this is because the flowers are very short-lived, but sadly the other reason is that they are restricted to forests of Borneo, Malaysia, and the Philippines, which are disappearing.