University of Tennessee
Forest Resources AgResearch and Education Center
Oak Ridge Forest Cumberland Forest Highland Rim Forest Arboretum

Leatherleaf Mahonia (Mahonia bealei)

Mahonia Plant Mahonia Leaves Mahonia Flowers
Leatherleaf Mahonia (also known as Beale's Mahonia) is a native of China that has been planted extensively and is a potential invader of Southeastern woodlands. This upright, evergreen shrub produces terminal clusters of fragrant yellow flowers near the end of February into early March. At the Arboretum, it is found along parts of the Tulip Poplar and Heath Cove trails, among other places, and is frequently observed under forest canopies and along forest edges in the Oak Ridge area. It has dark green, alternate pinnately compound leaves with sharp, spiny leaflets somewhat resembling holly leaves. This upright shrub produces grape-like clusters of bluish-gray fruits in early summer which are attractive to birds - a related species Mahonia aquifolium with similar fruit is known as Oregon Grape. The Tennessee Exotic Pest Plant Council lists Mahonia bealei in its "Alert" category because of its invasive characteristics.

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Lenten Rose (Hellebore) (Helleborus x hybridus)

Lenten Rose White Lenten Rose

Lenten Rose Plant One of the earliest flowers blooming in the Wildflower Gardens around the Arboretums Visitors Center is the Lenten Rose. A member of the Buttercup Family (Ranunculaceae), the nodding flowers of the Lenten Rose have five showy white to pink sepals which may persist into the early summer. In our area, the flowers may appear as early as January and often can be found through April. The common name reflects the blooming period which occurs during the season of Lent. The dark green compound leaves, which provide a good ground cover, arise from an underground stem the plants being referred to as acaulescent (without an aboveground stem). Helleborus species are native to Europe and China. Some of these species have been extensively hybridized, and Lenten Rose, although frequently referred to as Helleborus orientalis, is generally considered to be one of these acaulescent hybrids. All parts of the plants contain toxic alkaloid compounds, and may cause a mild skin rash if handled extensively. The plant is considered to be deer-resistant, and may be planted in areas subject to heavy deer browsing to reduce damage.

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Limber Pine (Pinus flexilis)

Limber Pine Bark Limber Pine, a conifer of the Rocky Mountains and Intermountain West, ranges from British Columbia and Alberta south to New Mexico, Arizona, and southern California. Limber Pine's natural habitat is usually dry, exposed ridges, and it can often be found at both lower and upper timberline. It is slow growing and may be long-lived - 1,000 years or more. An example of this western species, planted in 1990 as part of the Arboretum's Conifer Collection, has done well in our eastern environment.

Limber Pine Needles Limber Pine is one of several western white pines. It has yellow-green to bluish-green needles that are 1.5 to 3 in. long and usually borne in bundles of 5. The needles are densely tufted at the ends of the twigs and point forward. The branches and twigs are tough and flexible, giving rise to the epithet "limber" in the common name. Limber Pine grows to heights of 40 to 60 ft, although at high altitudes in its natural range, it may have a twisted and contorted growth form, forming a stunted forest known as "krummholz." The reddish to yellow cones are 3 to 10 in. long, and the seeds provide an important food source for small mammals, birds, and bears. The light gray bark is smooth on younger trees, but becomes dark brown and scaly with age.

The close-grained, resinous wood is poorly suited for lumber. Historically it has been used for mine timbers, cabins, railroad ties, fencing, and firewood.

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Little Brown Jug (Hexastylis arifolia var. ruthii)

Little Brown Jug Leaves Little Brown Jug is a perennial, evergreen wildflower that can be seen along many of the Arboretum's trails. Its unusual urn-shaped (or jug-shaped) flower is found at ground level, usually covered by leaves and other forest litter. The shiny, arrowhead-shaped leaves and glabrous flowers arise from an underground stem (rhizome). The sepals are fused into an urn-shaped, brown to reddish brown calyx tube (there are no petals) with pointed tips at the top. Within the urn are 12 stamens and a superior or partly inferior ovary having 6 styles.

Little Brown Jug Flowers Little Brown Jug belongs to the same plant family (Aristolochiacease) as Wild Ginger ( Asarum canadense), which has pubescent, heart-shaped leaves and a calyx tube that terminates in spreading or reflexed tips. The rhizome of both plants has an odor similar to ginger (as do the crushed leaves) and was used as a substitute for that spice by early settlers. Flowers of Little Brown Jug are pollinated by beetles and other insects in the leaf litter. Little Brown Jug is found throughout the Southeast. Native Americans used it for treating such ailments as stomach pains, whooping cough, heart problems, and asthma.

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Little-Leaf Linden (Tilia cordata)

Little-Leaf Linden Leaves Little-Leaf Linden Flowers Little-Leaf Linden Fruit

Little-Leaf (or Small-Leaved) Linden (Tilia cordata) is an interesting tree growing near the Sink Hole area behind the Arboretum's juniper collection. It has relatively small, heart-shaped, finely toothed, shiny dark green leaves. In late April to May it produces small fragrant creamy yellow flowers in clusters subtending distinctive lime-colored, papery bracts. Bees and other insects are attracted to the flowers, and it is considered to be a good honey tree. Fruits consist of clusters of brown nutlets subtended by the papery bracts and mature in early fall, often persisting into the winter months.

The tree can grow to heights of 60 to 80 ft with a spread of up to 40 to 50 ft. A native of Europe and the Caucasians, Little-Leaf Linden has been planted extensively in Europe and the U.S. as an urban/street tree because it tolerates air pollution, poor soil conditions, and drought. In Britain and Europe members of the genus Tilia are known as Lime or Linden trees. Tilia cordata flowers, leaves, wood, and charcoal have been used historically for a wide variety of medicinal purposes. An extract has been used in skin care products, detergents, makeup, and hair care products. The wood has also been used for carving and for making string and wind musical instruments.

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Lizard's Tail (Saururus cernuus)

Lizard's Tail A walk in the Marsh Area reveals a large colony of Lizards-Tail (also known as Water Dragon) growing along the creek bank. This aquatic plant has an inflorescence that resembles a bottle brush made up of a dense cluster of white flowers. As the fruits mature, the brown inflorescence is said to resemble a lizards tail.

Lizard'sTail Flower Lizard-Tail grows along ditches, streams, ponds, and in other wetland situations. It is a popular water garden plant. Over time, the plant has been used as a general medicine for a variety of illnesses. Lignan compounds and other chemicals in Lizard-Tail have been shown to provide it with chemical defense against aquatic herbivores such as crayfish. Recent biochemical studies indicate that compounds from this plant have potential for treatment of tumors.

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Loblolly Pine (Pinus taeda)

Loblolly Pine Pollen Cones Several large specimens of Loblolly Pine are found near the Arboretums 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.

Loblolly Pine Cones 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.

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University of Tennessee - Forest Resources AgResearch and Education Center
901 South Illinois Avenue, Oak Ridge, Tennessee 37830 · Telephone: 865-483-3571 · Email: UTforest@utk.edu