U.S.Forest Service, Washington, 1914, pp.

54-58.] The most common of the higher parasitic plants damaging timber trees are mistletoes.

Many species of deciduous trees are attacked by the common mistletoe (_Phoradendron flavescens_).

It is very prevalent in the South and Southwest and when present in sufficient quantity does considerable damage.

There is also a considerable number of smaller mistletoes belonging to the genus _Razoumofskya (Arceuthobium)_ which are widely distributed throughout the country, and several of them are common on coniferous trees in the Rocky Mountains and along the Pacific coast.
One effect of the common mistletoe is the formation of large swellings or tumors.