Tendril

[2] Tendrils respond to touch and to chemical factors by curling, twining, or adhering to suitable structures or hosts.

Normally there is only one simple or branched tendril at each node (see plant stem), but the aardvark cucumber (Cucumis humifructus) can have as many as eight.

[4] The earliest and most comprehensive study of tendrils was Charles Darwin's monograph On the Movements and Habits of Climbing Plants, which was originally published in 1865.

This work also coined the term circumnutation to describe the motion of growing stems and tendrils seeking supports.

In other plants such as the yellow vetch (Lathyrus aphaca), the whole leaf is modified to become tendrils while the stipules become enlarged and carry out photosynthesis.

If the tendril comes into contact with an object for long enough it will usually curl around it, forming a strong anchor point for the pitcher.

[6] Tendrils of Cuscuta, a parasitic plant, are guided by airborne chemicals, and only twine around suitable hosts.

[15] This cascade can activate plasma membrane H+-ATPase, which also plays a role in the contact coiling mechanism as a proton pump.

This pump activity establishes an electrochemical of H+ ions from inside the cell to the apoplast, which in turn creates an osmotic gradient.

[16] This contractile movement is also influenced by gelatinous fibers, which contract and lignify in response to the thigmotropic signal cascade.