American Senna

August 5th, 2020

Senna hebecarpa

This perennial member of the pea family (Fabaceae) is native to the area between Ontario eastward to Maine and southward to Georgia including Tennessee. It is found in Hardiness Zones from 4 through 9, thus, Chattanooga is a perfect area for the American senna.

physical description

This species produces large plants up to 6 feet tall that flower in July and August.  The bright yellow flowers attract bees, butterflies and other pollinators.  During autumn, the leaves undergo a remarkable color change again, adding accents to the garden.  While this plant is perennial it also is deciduous.

habitat

American senna prefers moist to medium moist loamy soils along with full sun to partial shade. It is often found in moist woods and disturbed areas such as road ditches and bridge embankments.

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uses

This plant is often used as a living hedge, effectively blocking access past it.  

It is used as a cover crop and food source for quail and other hunted bird species.

interesting information

While the light-yellow flowers of this plant are beautiful, the flowers, seeds and leaves have a toxin called anthraquinones and can cause a fatal situation, especially in children. This toxicity can be greater or lesser depending on a person’s age, weight, individual medical condition, and exposure. Children can be particularly susceptible.

This species has few diseases or insect pests that the home gardener needs to be aware of.

Due to the large tap root of this plant, dividing the roots in an effort to propagate it is often not possible. Instead, the gardener can collect the seed heads in late autumn and sow them in the early spring.  

According to iNaturalist, this species is currently found at Reflection Riding Arboretum and Nature Center.

In the northeast US this plant is state-designated as “endangered,” specifically in Pennsylvania, Massachusetts, Connecticut, Rhode Island, and Vermont. Here in Tennessee it is considered “secure,” with no restrictions on its distribution or care.

About the Author

Charlie Belin is a retired professor and biological oceanographer. He taught five courses in the University of Georgia system for many years from his home base in Savannah, Georgia.

Charlie loves hiking at Reflection Riding, teaching children about the ecology of the area, and interacting with the Reflection Riding staff. They are GREAT!

Posted by Charlie Belin  | Category: native plants

Obedient Plant

July 30th, 2020

Physostegia virginiana

The obedient plant is a rhizomatous, native perennial that is found from Quebec to Manitoba southward to New Mexico and Florida.

physical description

This attractive plant looks a bit like a snapdragon, but its square stem is typical of the mint family. They grow to a height of approximately 4 feet, and to 6 feet under optimal conditions. If the flowers are bent, they tend to stay in the new position for a while, thus the common name "obedient plant."  Several garden forms occasionally “escape” to the wild. Flowers can be either white or pink, and recent research has developed a purple variety, too.

habitat

The obedient plant can grow in either full sun, partial shade, or full shade. It prefers a moist, humus, well-drained soil.

The obedient plant can be propagated by dividing the roots in the autumn or via seeds, which can be ordered online. The divisions should be planted in the autumn and the seeds sown in late autumn or early spring.

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uses

This moderately large plant makes a fine background to block an area such as a building foundation, a wall, or out-buildings.

This species often attracts hummingbirds, butterflies, and other pollinators.

interesting information

All members of this large family (the mint family or Lamiaceae) have a stem that, in cross section, is square.  This includes not only the obedient plant but also the mints, lavender, rosemary, hyssop, basil, and many of the other edible herbs we use every day.

The obedient plant has no serious insect or disease problems.

Rust can be an occasional problem.

Be on the lookout for aphids and spider mites which can be controlled using an insecticidal soap rather than a pesticide.

Species plants and the varieties can be aggressive spreaders; however, it can be controlled since the shallow roots are easy to pull out.

This perennial is easy to establish and requires only medium maintenance.

About the Author

Charlie Belin is a retired professor and biological oceanographer. He taught five courses in the University of Georgia system for many years from his home base in Savannah, Georgia.

Charlie loves hiking at Reflection Riding, teaching children about the ecology of the area, and interacting with the Reflection Riding staff. They are GREAT!

Posted by Charlie Belin  | Category: native plants

Impatiens capensis

Jewelweed is a common self-seeding native annual that grows widespread throughout North America. Named for its vibrant flowers, jewelweed sprouts inearly spring. Flowers bloom in mid-summer and continue until the first frost.

Hardy in Zones 2-11, it is well-suited for native plant gardeners, pollinator-friendly gardeners, and medicinal gardeners anywhere in the contiguous United States. Legend has it that European plant hunters in North America loved the flowers so much that they shipped seeds back home!

physical description

The orange-yellow flowers — sometimes peppered with red spots — distinguish this plant from other “touch-me-nots.” The flowers have five petals, though it may look like just three, and the “open mouth” offers a landing pad for many pollinating insects.

This species grows 2 to 5 feet in height. The leaves are green with a whitened underside and the shape is ovate with coarsely toothed margins and are usually 2 ½ to 3 inches long. They grow in an alternating pattern. The stems are smooth, upright, weak, and sometimes have a red tinge. After rain, the plant soaks up water and the stems become almost translucent.

Cross-pollination is required for the plant to produce its small, green fruit, which bursts open and spreads seed at the slightest touch; this is where it gets its nickname, “spotted touch-me-not.” Small flowers, which fertilize themselves without ever opening, may develop at the base of the plant in fall and produce small seeds.

habitat

Jewelweed prefers moist, semi-shady areas near streams and lakes and in disturbed areas such as ditches and roadsides. It has been shown to outcompete garlic mustard, a non-native invasive weed, and can be easily propagated by sowing seed directly in early fall.

In ideal conditions, jewelweed grows in dense stands and attracts bumblebees, butterflies, and hummingbirds.

This species is moderately deer resistant. It is low maintenance and very easy to control or corral by pulling.

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All images licensed under CC BY-NC-SA 2.0.

uses

Jewelweed doesn’t mind wet feet, so it makes a great addition to shady rain gardens or native plant gardens in partially-shaded areas with plenty of moisture. Because it is such a star at outcompeting other plants, it can be planted to suppress unwanted non-natives or fill in open areas. Once it is established, it will continue to return every year.

Jewelweed is well-documented as a medicinal plant among several Native American tribes, including the Cherokee. In modern-day folk and wilderness medicine, sap from the stem and leaves is applied topically to treat pain and/or itching from hives, poison ivy, insect bites, sunburn, and even unfortunate run-ins with stinging nettle.

protection status

Although conservation status is secure, humans are impacting the plant through destruction of wetland habitats, so it could become imperiled in the future. Help to maintain the security of Impatiens capensis by growing it on your
property and telling others about it!

interesting information

Jewelweed boasts a sugar content considerably higher than many other flowers favored by hummingbirds. In fact, the southbound migration of ruby-throated hummingbirds has been found to coincide with the availability of jewelweed’s
blooms.

The common eastern bumblebee AKA Bombus impatiens, considered one of the most important species of pollinator bees in North America, is named for one of its primary good sources: the genus Impatiens of which jewelweed is a member.

About the Author

Taylor Hinton-Ridling is a wildcrafter and native plant enthusiast in Chattanooga. She enjoys hiking and learning about plants, animals, and ecology at Reflection Riding.

Posted by Bess Turner  | Category: native plants

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