Codariocalyx motorius (Desmodium gyrans), seeds of Telegraph- or Dancing plant

Codariocalyx motorius (Desmodium gyrans), seeds of Telegraph- or dancing plant

Codariocalyx motorius belongs to the family of the Fabaceae, the leguminous plants. The plant is native to Asia and India. It is also known as telegraph plant or dancing plant. In former times the plant had the scientific name Desmodium gyrans but nowadays it is known as Codarocalyx motorius in the systematic. Already Charles Darwin described the plant in detail in 1880.
C. motorius is a perennial shrub that reaches a height of about 120 cm.
The leaves of the telegraph plant are pinnate. The leaflets at the side are much smaller than the leaflet at the end. The leaflets at the side get only 1 to 2 cm long and 3,5 to 4 mm wide whereas the leaflet at the end gets 7 cm long and 1 cm wide. In the night the leaves point all downwards. During daytime they stand normally horizontal at the shoot. The sleeping position of the leaves is not due to temperature or other factors from outside. It is just the circadian rhythmic of the plant. Another feature of the plant is that the leaves can move. This movement is visible without any technical help. That is why the plant is called dancing plant. Until today one does not know why the leaves move. One has observed that the leaves move when they are exposed to music with a high frequency or when the temperature changes. One suggests that the leaves move because the plant wants to use as much sunlight as possible for photosynthesis. What one surely knows is that the movement is due to a pressure change in the end of the petiole. The leaf needs 3 minutes for one turning. The statement that the plants communicate via the movement as one said in former times is surely not right.
The flowers are zygomorphic, hermaphrodite and purple in color. The telegraph plant does mostly not bloom in the first year. The flowers stand together in inflorescences. The fruit is like it is typical for a Fabaceae, a legume.
In Europe it is used as an ornamental plant because of its dancing skills.

Cultivation

The seeds of C. motorius should be put 72 h into warm water before planting. After that they can be put onto the substrate. One should only cover the seeds slightly with substrate and place it sunny. When the substrate is kept moist at a temperature of about 20 to 25 °C, germination occurs after just one week. The telegraph plant is not winter hardy.