Unit 009

1. Parasitic Plants on Beech and Oak Tree Roots

Beechdrops or Epifagus virginiana, is a visible brown parasitic plant that is found

on American Beech (Fagus grandifolia) roots. Check the photos so you can look

for these plants. They are not harmful to the tree, and are often found several feet

away from the tree trunk. They are thin brown plants about a foot or so tall.

Squawroot or Conopholis americana is another harmless parasitic plant on Oak tree

(Quercus) roots. These are short, fat, yellowish brown, and often found in clumps.

One article says they are a part of the bears diet in the southern Appalachian

 mountains.

2. Quercus or Oak subgenera

Quercus or Oaks are often divided into subgenera. Two key subgenera are:

a. Subgenus Leucobalanus or the White Oak Group.

Leaves are mostly with rounded lobes, and acorns mature in one season. Seed are

usually sweet.

b. Subgenus Erythrobalanus or the Red Oak Group.

Leaves are bristle tipped, and acorns usually mature in two seasons. Seeds are often

bitter.

Plants in the Red oak group are more susceptible to Oak wilt disease, although it

can affect white oak group oaks.