Plants modify the growth path of their stems and different appendages depending on the sunlight . In nature, this occurs in various ways. For example, in the case of climbing plants, such as the vine, these usually have tendrils, hooks or thorns that act as attachments to climb any type of structure, including those of other plants. To aid in the ascent, the stems and shoots are twisted following the surface of the object in question. The speed at which the structures go around depends quite a bit on the genre and the conditions they face.
In his book The movements and habits of climbing plants , Charles Darwin claimed that those of the genus Scyphanthus are the fastest; based on their observations, they complete one revolution (one lap) in one hour and seventeen minutes. Scyphanthus is a genus of flowering plants in the Loasaceae family, which are native to Africa and America. The family comprises annual, biennial and perennial herbaceous plants and a few shrubs and small trees.
However, the tendrils of some species of Passiflora sometimes do it even faster and the filaments of the vines are capable of turning in as little as an hour. Even species of the same genus can move at different speeds, a variation that has nothing to do with the thickness of the shoots or appendages. Most of them rotate in an anti-clockwise direction , others do it in the same direction and some, such as those of the genus Fallopia – many of them invasive species – can rotate in both directions. None chooses it on the fly, but the preferred direction of rotation is genetically determined.
Image credit: Thierry Tronnel / Corbis
