The Living World 6th Edition by George Johnson, Jonathan Losos,William Ober,Claire Garrison

Exercise 20

If it is out in the open, trailing ivy grows along the ground and can form dense mats of ground cover. If planted in a hanging pot, the stems dangle down, forming a graceful flow. If ivy is planted next to a building, however, its stems attach to the side of the building and, in time, it will cover the building. What causes this