telegraph plant

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A tropical Asian plant (Codariocalyx motorius) in the pea family, having trifoliolate compound leaves whose two small lateral leaflets move by jerks in response to sunlight.

from The Century Dictionary.

• noun The East Indian Desmodium gyrans, a plant with trifoliolate leaves, of which the lateral leaflets are very small and remarkable for their spontaneous jerking motion, suggesting signaling.

from the GNU version of the Collaborative International Dictionary of English.

• (Bot.) A tick trefoil (Meibomia gyrans formerly Desmodium gyrans), native of the East Indies; it is a leguminous plant whose lateral leaflets jerk up and down like the arms of a semaphore, and also rotate on their axes.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun erect tropical Asian shrub whose small lateral leaflets rotate on their axes and jerk up and down under the influence of sunshine