Re: Are there plants evolved now that feed on other plants?

Elizabeth,

Yes, although they do not chew up the other plants like we do. They are more like sucking insects in that parasitic plants tap into the host plant's vascular system and remove nutrients that way. There are a few thousand species of parasitic plants, which steal organic nutrients, water and mineral nutrients from other plant species or just water and mineral nutrients. Some parasitic plants cannot photosynthesize so they are completely dependent on their host. Examples include dodder and Rafflesia, the world's largest flower. Other parasitic plants can photosynthesize so mainly steal water and mineral nutrients from their host. A familiar example is mistletoe. So-called myco-heterophytes, such as Indian pipe, are also nonphotosynthetic. They have a fungus which steals nutrients from a photosynthetic tree and transfers them to the myco-heterophyte. Parasitic plants and myco-heterophytes are true plants that produce flowers and seeds.

David Hershey

Reference
Hershey, D.R. 1999. Myco-heterophytes and parasitic plants in food chains. American Biology Teacher. 61:575-578.