The University of Tennessee - Forest Resources Research and Education Center

Among the interesting ferns found at the Arboretum is the Resurrection Fern which can be observed on several Eastern Red Cedar trunks along the Cemetery Ridge Trail. It also occurs on rocky ledges off the trails. The fern is an epiphyte (or air plant) — a plant that uses another plant as a substrate but does not depend on that plant for food, nutrients, and water as does a parasitic plant.

During dry periods, the fern’s fronds appear shriveled. The common name is based on the fern’s ability to expand quickly (i.e., resurrect) in response to a rainy period, such as the rain we had at the end of August. The fern obtains its water and nutrients directly from rainwater and the wet bark or other substrate on which it grows. Resurrection Fern is widely distributed in Tennessee and the Southeastern U.S.

Honey Locust (Gleditsia triacanthos)

As you walk along Marsh Road, you will find two large trees with large thorns on their trunks. These Honey Locusts (or Sweet Locusts) have abundant yellowish, bean-like pods hanging down from the branches. The compound leaves are bi- or tri-pinnate (leaves divided two or three times). The native range of Honey Locust extends from central Pennsylvania south along the Appalachians to Alabama and west to Texas and the Central U.S.

Honey Locust belongs to the plant family Fabaceae (the bean or pea family). The large pods, which are yellowish now, turn brown as fall progresses and may persist into winter. The pods are sweet and eaten by cattle, hogs, and wildlife (thus the name "honey" or "sweet"), and the rattling of the seeds in the pods is said to resemble the singing of locusts (thus the second part of the common name).

The conspicuous thorns on the trunk and limbs are modified branches—they occasionally bear leaves. These have likely evolved over geologic time as protection against large herbivores. In the past, the very hard thorns have been used as nails, for carding wool, and as pins for closing sacks. The durable wood has been used for railroad ties, fence posts, and pallets. A number of thornless varieties have been developed for shade and ornamental use.

Eastern Red Cedar (Juniperus virginiana)

A former Eastern Red 'Cedar Barrens' being replaced by deciduous forest.

Eastern Red Cedar (also known as Old Field Juniper) is a small to medium sized coniferous tree with scale-like or awl-like leaves and bluish, berry-like fruits. It is widespread throughout the eastern U.S. and adjacent Canada. It invades open areas that have been disturbed by fire or cleared for agriculture. Areas dominated by Eastern Red Cedar are referred to as “Cedar Barrens” and are present in the Oak Ridge area. Eastern Red Cedar trees may persist in older forests for many years, and their presence may provide evidence of past land use for agriculture or other human or natural disturbance.

The female cones of Eastern Red Cedar develop into bluish “berries” with a waxy coating. These fruits are an important winter food source for birds, which disperse the seeds widely.

The aromatic wood repels insects and is used for lining cedar chests and as fence posts. The tree is also planted for windbreaks and used for making pencils and for Christmas Trees in the South. It is an alternate host for cedar-apple rust and should not be planted near fruit trees .

Fall Flowers

Mid to Late September

A walk along Scarboro Creek below the Magnolia Orchard and in the Marsh Area provides a good view of a variety of fall wildflowers along the stream banks. A sample of these are highlighted at left. Clockwise from upper left: Spotted Touch-Me-Not (Impatiens capensis), Cut-Leaf Coneflower (Rudbeckia laciniata), Turtlehead (Chelone glabra), Cardinal Flower (Lobelia cardinalis), Great Blue Lobelia (Lobelia siphilitica). Center: Sweet Joe-Pye Weed (Eupatoreum purpureum).

Persimmon (Diospyros virginiana)

Persimmon is a moderately sized tree growing to 60 feet tall and 2 feet in diameter. It is the most northern member of the Ebony family — other members of the family are tropical or subtropical. A Persimmon tree found just above the end of the Tulip Poplar Trail is currently loaded with orange fruit that will become deep purple as they mature during the next few weeks.

Persimmons are dioecious — meaning that male and female flowers are found on separate trees. The leaves and fruits of the tree are astringent, and have been described as puckery. However, when mature, the fruits lose their astringent tannins and become sweet and delicious. The genus name Diospyros can be translated from the Greek as ”food for the gods.”

Persimmon is native to the Eastern U.S. — New England to Florida, west to Texas, Iowa, and Kansas. The bark is dark brown to black and is deeply divided into small blocks. The dense wood has been used for such purposes as golf club heads and billiard cues.

Chinese Chestnut (Castanea mollissima)

Late September to Early October

At this time of year, the ground below two Chinese Chestnut trees upslope from the Arboretum Visitors Center is littered with large spiny chestnut burs (up to 3 in. long and over 1 in. in diameter) that quickly open to reveal one to three dark brown nuts. These 20-year-old trees are resistant to chestnut blight which virtually eliminated American Chestnut from the Eastern Deciduous Forest of North America.

Chinese Chestnut cultivars are being crossed with American Chestnuts in efforts to develop a chestnut hybrid resistant to chestnut blight. Old stumps of American Chestnut can be seen along the Lost Chestnut Trail and elsewhere on the Arboretum. Sprouts from these stumps can occasionally be found, but they generally succumb to chestnut blight after a few years.

Resurrection Fern (Pleopeltis polypodioides)

Honey Locust (Gleditsia triacanthos)

Eastern Red Cedar (Juniperus virginiana)

Fall Flowers

Persimmon (Diospyros virginiana)

Chinese Chestnut (Castanea mollissima)