How Can Some Plants Climb a Smooth Wall?
To get at the answer to this question, we should pick out one kind of plant like the creeping ivy vine. If we examine same as it climbs a brick wall, we find that it sends out little shoots which attach themselves around the little rough places in the bricks of the wall which, if examined under a microscope are quite large apparently—at least they are large enough for the tiny creepers of the ivy to hold on to. Of course, if there were only one little “shoot” to reach out and take hold of the rough spots in the wall, the vine could not cling to the wall, but the vine puts out a great many of these shoots—which it would perhaps be best to call “clingers” and as each helps a little to hold on, the great number all holding on together enable a quite heavy vine to hang on to an apparently smooth wall.
Some vines have actually the ability to send out little suckers which are made on the same principle as the boys’ sucker (a circular piece of leather with string attached to the middle with which a boy can pick up stones) and such plants can cling to and climb up an almost perfectly smooth wall.