Read it through once

It is impossible not to be impressed with the extraordinary variety of all these contrivances by which plants are able to escape the trouble of supporting themselves. But such ways of life involve certain disadvantages. Supposing there is nothing on which to climb, the stems trail feebly on the ground, and are probably soon choked by the surrounding grasses. Curiously enough, there are varieties of the Ivy, Wistaria, and the French Bean which are upright, and do not climb at all. The Tree Ivy has all its leaves like the leaves of the flowering shoot in the common form. In America, _Wistaria sinensis_ is often grown as a standard tree, and does not send out the long shoots, sometimes thirty feet in length, which are common when it grows on walls. The dwarf French Bean has a thick stem and requires no support, yet it often puts out a long slender shoot which tries to twine round something.