While this page is being developed, you can see here some remarkable examples of plants exhibiting different sensory sensitivities. At the bottom of the page is an excellent article on plant intelligence.
This video (from the lab of Consuelo M. De Moraes at Penn State university) shows a parasitic Cuscuta (dodder) plant (the spindly thing on the left) searching for a tomato plant to live off of. The Cuscuta identifies the tomato by smelling it. The tomato gives off of an aroma that the Cuscuta is attracted to. Interestingly, this aroma is specific to tomato, and Cuscuta won't grow to wheat for example!
Proprioception: Gravitropism in an Arabidopsis root
The Venus Fly Trap literally feels its prey. Notice that both the fly and the frog have to make their way across the trap before it closes. This is because the prey has to touch at least two of the big black hairs on the pink surface of the trap before it will close.
Here you see a root from Arabidopsis. The plant was places horizontal on its side, and the root reorients its growth to go down vertically. Produced by PhytoMorph at the University of Wisconsin.
Early movies of plant movements
This video was produced by Cameron Wright for his 3rd grade science project! The direction of the light was shifted every 12 hours.
Dancing sunflowers
by kinetoscope Wilhelm Friedrich Philipp Pfeffer (1845 - 1920) was a German botanist who was one of the first to use time-lapse photography to study plant movements
The dynamic nature of circumnutation nutation of sunflower is illustrated. The images were captured every 20 min under continuous white light, and the movie is played back at 12 frames per sec. The entire movie represents a 2-day period and was kindly provided by Roger P. Hangarter of Indiana University, Bloomington.