Observations on the Mistletoe (Phoradendron flavescens) in South Mississippi, with Special Reference to the Mortality of Quercus nigra.

ABSTRACT
<em>Phoradendron flavescens</em> (Pursh) Nutt. is found on seven species of trees in south Mississippi; the most common host is the water oak, <em>Quercus nigra</em>. Undisturbed forests with closed canopies have significantly fewer infected trees than disturbed forests with open canopies. Initial infection of an individual water oak generally occurs on the distal portion of the branches, followed by multiple infection of the same and other inner or proximal branch portions. Branch segments between infection sites die sequentially from the distal branch portion inward to the tree trunk. Isolated trees are quickly killed. Tree death occurs when most of the outer branches are pruned. The susceptibility of water oaks to infection is partially attributed to the very thin bark of branches and trunk; however, the high incidence of infection cannot be explained.