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A large Korean White Pine tree highlights part of the Arboretum’s conifer collection across from the Program Shelter and adjacent to the oak collection. This native of NE Korea, Japan, Manchuria, and eastern Russia is found in mountain forests. It is similar to our native White Pine (Pinus strobus) in having 5 needles (2-5 in. long) per bundle, and elongate cones (3.5-6 in. long) borne on short peduncles (stalks).

The gray to gray-brown bark is broken into irregular oblong plates. This tree is referred to as the Korean Nut Pine because the seeds are edible and can be eaten raw or cooked as a staple food. They are also used for flavoring and as a thickener. The seeds have been used medicinally for their analgesic, antibacterial, and anti-inflammatory properties, and the turpentine obtained from the tree has been used for a wide variety of treatments. This tree is considered good for bonsai.

It's always somewhat surprising to find wildflowers in January, but despite this month’s cold temperatures, a shrub next to Scarborough Creek just below the Arboretum Visitors Center was in full bloom. Vernal Witch Hazel is a native of the Ozark and Ouachita Mountains. Its very fragrant flowers vary in color from yellow to purplish-red and usually bloom in January or February. The common name Witch Hazel purportedly comes from the belief that witchcraft allowed the crooked stems of the shrub to be used for divining water.

The flowers of our native American Witch Hazel (Hamamelis virginiana) have 4 yellow strap-shaped petals and are less showy than those of Vernal Witch Hazel. Witch Hazel belongs to the plant family Hamamelidaceae. The only other genus in this family native to the U.S. is Sweetgum (Liquidambar).

Several large specimens of Loblolly Pine are found near the Arboretum’s Program Shelter, and research plantings that were established in 2003 can be seen along Arboretum Drive. The needles of Loblolly Pine are typically borne in fasicles (bundles) of 3 (sometimes 4) — the yellow-green needles are longer (6-9 in.) than those of Virginia Pine and Shortleaf Pine. The elongate, cylindrical seed cones (6-9 in. long) mature in 2 years and do not persist on the trees as do those of Virginia Pine. Pollen cones appear in April and produce large amounts of pollen. The bark on older trees is dark gray-brown and deeply furrowed.

The native range of Loblolly Pine extends from southern New Jersey, south along the Coastal Plain and Piedmont regions to Florida, and west to eastern Texas. In Tennessee its native range extended only into the southern edge of the state, but it has been widely planted and is commonly seen along highways and in tree plantations in our region. It is an important pulpwood and timber tree throughout much of the Southeast.

Virginia Pine (also known as Scrub Pine) is one of the more common native pines found at the Arboretum. Its twisted, yellowish-green needles are borne in bundles of two, a characteristic that helps distinguish it from Shortleaf Pine which has straight needles in bundles of 2-3. Trunks of older Virginia Pine retain many dead limb stubs below the canopy. The flaky bark is light brownish orange to gray-brown. The seed cones, which require 2 years to mature, have scales with thickened ends bearing slender, stiff prickles. Pollen cones develop in the spring and produce copious amounts of pollen.

Virginia pine, which may grow up to 70 ft in height, is a pioneer species that becomes established in open areas created by fire or other disturbance. The presence of older Virginia Pines in the Arboretum’s deciduous forest reflects a history of forest development on abandoned farmlands. Research at UT on Virginia Pine has included studies of genetic and environmental variability that influence tree growth and productivity.

A walk along Cemetery Ridge Trail during our first snowstorm of the year (December 5, 2009) highlighted the bright red fruits of the Oriental Bittersweet vines that climb and, in some cases, cover some of the trees and shrubs along the trail. The fruits are initially green, but become bright yellow at maturity. When the yellow capsule breaks open in the fall, it reveals a fleshy red aril which contains two brown seeds.

The small greenish flowers develop in the spring (at the end of April this year). Each flower is typically unisexual — either male or female, but some perfect flowers occasionally develop. The leaves are rounded to acute/elliptic, the latter shape being more common at the end of young developing shoots.

This invasive woody vine was introduced to the US in the mid- to late 1800s and is especially troublesome in New England, the Atlantic coastal states, and the southern Appalachians. The vine aggressively twines around tree and shrub stems and can strangle (by girdling) or completely covers and shades out its hosts. The fruits are eaten and spread by birds. People also inadvertently help spread the attractive fruits which they gather for holiday decorations. Such decorations should be destroyed completely after the holidays to limit the spread of this invasive plant. At the Arboretum, Oriental Bittersweet is most common in relatively open areas along forest edges and is one of several invasive plants the Arboretum staff is attempting to eradicate.

The area currently occupied by the Arboretum was mainly farmland when the government took it over in the early 1940s. Shortleaf Pine and Virginia Pine (P. virginiana) were two of the trees that first invaded the abandoned farmlands. These pines grow in the open, where competition from other trees for light, moisture, and nutrients is limited. As the forest developed, deciduous species such as oaks, hickories, and tulip poplar, gradually became established and have become the dominant trees. Recent research at the UT Forest Resources Center in Oak Ridge and the Chuck Swan State Forest near Norris evaluated the historical development, current conditions, and future potential of the Shortleaf Pine resource and found that this species flourished in the past as a result of repeated disturbance from fire, logging, and clearing for farmland and other developments. However, these types of disturbances and associated reforestation patterns have been virtually eliminated in much of our region, so that little Shortleaf Pine regeneration occurs today. Although some older individual Shortleaf and Virginia pines are still present at the Arboretum, these trees are gradually dying out. Southern pine beetle infestations in recent years have hastened the demise of these pines, and remnants of their trunks are scattered through-out the forest floor. Virginia Pine is described in the February Featured Plants.

Shortleaf pine can be recognized by it’s platy bark, straight needles (3-5 in. long) borne in fascicles (bundles) of 2-3 and a flat-topped crown. The seed cones, which mature in 2 years, are ovoid to conic in shape with stout, sharp prickles on the umbo (a knobbed protuberance on the cone scales). Shortleaf Pine is an important timber tree in the South-east, with its wood used for lumber, plywood, boxes and crates, and pulpwood.

Dawn Redwood is a deciduous conifer with flat, needle-like leaves that turn a copper-colored brown in November before falling to the ground. A tall specimen of this tree, planted in 1965, can be found at the upper end of the Arboretum’s Marsh Area. Dawn Redwood is related to the Southeastern Bald Cypress (Taxodium distichum) and California’s Redwood (Sequoia sempervirens) and Giant Sequoia (Sequoiadendron giganteum). In the early 1940s, a Chinese paleobotantist recognized that fossils initially thought to belong to the genus Sequoia should be reassigned to a new genus, Metasequoia. In 1945, living individuals of Metasequoia glyptostroboides were found in the Sichuan Province of China. Extensive field surveys in the late 1940s found this “living fossil” present in limited populations in Sichuan and neighboring Hubei Province.

Propagation of seeds and cuttings at arboreta in the U.S. and elsewhere have resulted in Dawn Redwood becoming available for planting. This conifer is fast growing, and, although the oldest U.S. trees were planted in 1948, some have attained diameters of over a meter. Dawn Redwood can be distinguished from Bald Cypress by several characteristics - the buds develop on the underside of the branches rather than along the tops as do those of other conifers; the base of the trunk is fluted and buttressed; and the branches have rounded depressions below their junction with the trunk.

A recent addition to the Arboretum’s plant collections near Scarborough Creek below the Visitors Center is a shrub with highly contorted branches. Harry Lauder’s Walking Stick (also known as Contorted Filbert or Corkscrew Hazel) is a cultivar of European Hazel and belongs to the same genus as American Hazelnut and Beaked Hazel, both of which can be found in Tennessee. A larger specimen of Harry Lauder’s Walking Stick has been growing for many years with the Arboretum’s Dwarf and Unusual Conifer Collection.

This cultivar is named after a famous Scottish comedian and singer who used a crooked cane as a prop during his performances in the late 1800’s and early 1900’s. He traveled widely and was knighted in 1919 by King George V for his many contributions to the war effort during World War I. He continued supporting the troops during World War II. The curling, twisted branches are most conspicuous during the winter after leaf fall.

As its name reflects, Shingle Oak has a long history of use for making shingles. Early French colonists in Illinois found that the wood could be split into thin sheets and was also resistant to decay. The distribution of Shingle Oak is centered in the Midwest extending south to Tennessee and Arkansas and east to Pennsylvania and Maryland. In Tennessee, it is most common in the central portions of the state.

The oblong to lance-shaped, dark green leaves have a short bristle tip. Three Shingle Oaks are present in the Oak Collection near the Arboretum’s Program Shelter. They are readily recognized at this time of year because the dark green leaves have yet to change color. As is true for other members of the Red Oak group, the small brown acorns require two years to mature .