Carolina Horse-Nettle, Carolina Horsenettle (Solanum carolinense L.)

Solanaceae (Potato Family)

USDA Native Status: Native to U.S.

Photographic Location: Wilson County TN

Star-like, white or pale lavender flowers with yellow centers are in lateral clusters on a prickly, erect stem.

A coarse, native, deep-rooted perennial, it is considered a weed by some, yet the flowers are attractive. Deep hoeing is needed eradicate the underground stems, and gloves must be worn while handling the plant. This plant is not related to the true nettles. Silverleaf Nettle (S. elaeagnifolium), a very similar plant with silvery foliage, occurs in the western United States east to Missouri and is adventive further east. Buffalo Bur (S. rostratum), an annual with bright yellow flowers, is naturalized from the western United States as a weed in fields.

Canada Cockleburr (Xanthium strumarium var. canadense (P. Mill.) Torr. & Gray)

Asteraceae (Aster Family)

USDA Native Status: Native to U.S.

Photographic Location: Cumberland Mountain State Park, TN

A cocklebur was the inspiration for a Swiss engineer, George deMastral, in 1948, for the invention of Velcro. He examined the burs that stuck to his socks and discovered that they consisted of hundreds of tiny hooks, which attached themselves to anything loopy.

Blackberry Lily (Belamcanda chinensis)

Iris family (Iridaceae)

   Description: This introduced plant has sword-shaped alternate leaves about ¾–2' long; they originate primarily toward the bottom of the flowering stalk. These leaves are often grouped together into the shape of a fan; they are green to grey-blue, linear in shape, glabrous, and glaucous. Their margins are smooth, while their veins are parallel. The erect central stalk is 2–3½' tall and either branched or unbranched; it is terete, fairly stout, glabrous, glaucous, and pale green. This stalk terminates in a cyme or compound cyme of flowers. There are pairs of small linear-lanceolate bracts at each fork of the stalk; these bracts are slightly membranous and tend to wither away. Each flower spans about 1¼–2" across, consisting of 6 spreading tepals, 3 distinct stamens, a style with a tripartite stigma, and an inferior ovary. The tepals are orange with purple dots and elliptic-oblong in shape, while the ovary is green, glabrous, and narrowly ovoid. Each cyme usually produces several flowers. The blooming period occurs from mid- to late summer and lasts about 1-2 months. There is no noticeable floral scent. Each flower is replaced by an oblongoid seed capsule about 1" long; the 3 sides of this capsule become strongly recurved, revealing a mass of shiny black seeds that resembles a blackberry. The root system consists of a thickened crown at the base of the plant, which has fibrous roots underneath; spreading rhizomes are also produced. Both the crown and rhizomes have an orange interior. This plant can spread by either rhizomes or seeds.

    Cultivation: The preference is full or partial sun, moist to dry conditions, and soil that is loamy, rocky, or sandy. The flowers and foliage are rarely bothered by disease or insect pests.
  
    Range & Habitat:  Wide spread in TN and the eastern U.S. A native of Asia, now well established as an escape. Habitats include thin woodlands, rocky bluffs, hillsides, fallow fields, roadsides, and sites of old homesteads. Blackberry Lily was introduced from East Asia as an ornamental plant and it is often cultivated in gardens because of the attractive foliage and flowers.

    Faunal Associations: Very little is known about floral-faunal relationships for this introduced plant. The flowers offer nectar and pollen to insects and other floral visitors, but it unclear who these visitors are. There are anecdotal reports that the seeds are eaten by birds.

    Photographic Location: Sycamore Ridge Ranch

    Comments: This remarkable plant has the leaves of an iris (Iris sp.), the flowers of a lily (Lilium sp.), and a fruit that resembles a blackberry (Rubus sp.). There is nothing that quite resembles it. The flower of Blackberry Lily has only 3 stamens, while the flower of a lily has 6 stamens. The Blackberry Lily differs from other members of the Iris family in having 3 distinct stamens that are not petal-like in appearance. It is still unclear whether the Blackberry Lily will become invasive. Another common name of this species is the Leopard Lily.

Hoary Mountain Mint, Silverleaf Mountain Mint (Pycnanthemum incanum (L.) Michx.)

Lamiaceae (Mint Family)

USDA Native Status: Native to U.S.

This stiff, erect, clump-forming mint has whitened leaves subtending the flower clusters. The minty-smelling plants are 3-6 ft. tall and have terminal flower clusters composed of numerous, small, two-lipped corollas varying from whitish to lavender, with purple spots. Small, white to lavender flowers in dense rounded clusters in leaf axils or atop a hairy square stem and branches; white bracts beneath flowers.

Photographic Location: Long Hunter State Park, Middle TN

The genus name derives from the Greek for dense and flower and aptly describes the crowded flower clusters. The many species are closely related and difficult to distinguish from one another. These plants, particularly the flower clusters, have a very strong odor when crushed.

Common Sunflower (Helianthus annuus L.)

Asteraceae (Aster Family)

USDA Native Status: Native to U.S.

Common sunflower is a widely branching, stout annual, 1 1/2-8 ft. tall, with coarsely hairy leaves and stems. The terminal flowers heads are large and showy, up to 5 in. across. A tall, coarse leafy plant with a hairy stem commonly branched in the upper half and bearing several or many flower heads, the central maroon disk surrounded by many bright yellow rays. Yellow ray flowers surround brown disk flowers.

Photographic Location: Wilson County, TN.

The state flower of Kansas. The heads follow the sun each day, facing eastward in the morning, westward at sunset; the name in Spanish means turns toward the sun. The plant has been cultivated in Central North America since pre-Columbian times; yellow dye obtained from the flowers, and a black or dull blue dye from the seeds, were once important in Native American basketry and weaving. Native Americans also ground the seeds for flour and used its oil for cooking and dressing hair. In the 19th century it was believed that plants growing near a home would protect from malaria. In the United States and Eurasia seeds from cultivated strains are now used for cooking oil and livestock feed. Many variants have been developed, some with one huge head topping a stalk 9-16 ft (3-5 m) tall, others with maroon rays. 

Wild Sweet Potato (Ipomoea pandurata)

Morning Glory family (Convolvulaceae)

Description: This perennial plant consists of a twining vine up to 20-30' long. It will climb adjacent vegetation readily, or sprawl across the ground in open areas. The terete stems are usually hairless, but sometimes pubescent, and often reddish purple. Along the stems are alternate leaves up to 6" long and 4" across. These leaves are usually cordate and hairless, although sometimes the smaller leaves are ovate. They have long hairless petioles and smooth margins. Both the upper and lower surfaces of the leaves are olive green, while the petioles are often reddish purple.

Flowering stalks develop from the axils of the leaves; each flowering stalk has a cluster of 1-5 funnelform flowers. The corolla of each flower is white, except for rosy pink or reddish purple coloration deep within its throat. The corolla has 5 shallow lobes; it is about 2½-3" across when it is fully open and similarly in length. The stamens of the flower are white; they project slightly from the throat of the corolla. The blunt overlapping sepals are light green, hairless, and about ½-¾" long; they often have narrow ridges. The flowers bloom during the morning (or during the afternoon on cloudy days), and they are individually short-lived. However, a typical plant will bloom for about 2 months during mid- to late summer. Each flower is replaced by a 2-celled capsule that contains 2-4 seeds. These flat seeds are conspicuously hairy along their outer edges, and pubescent elsewhere. The root system produces a large tuber that can lie several feet beneath the ground surface and weigh up to 20-30 lb.

Cultivation: The preference is full to partial sun and mesic to dry conditions. The type of soil is not particularly important; this plant often grows where there are rocky or gravelly slopes. Growth can be rampant where the soil is moist and fertile; this plant can smother surrounding vegetation and it prefers some kind of structural support. Drought resistance is very good.

Range & Habitat:This plant is more often seen in disturbed habitats, but it can be found in higher quality habitats as well.

Photographic Location: Wilson County, TN

Faunal Associations: The flowers primarily attract long-tongued bees, including honeybees, bumblebees, and digger bees (Melissodes spp.). Some oligolectic bees that visit the flowers of the Wild Sweet Potato and other Ipomoea spp. include Melitoma taurea (Mallow Bee) and Cemolobus ipomoea (Morning Glory Bee). These insects seek nectar primarily, although the oligolectic bees collect pollen as well.  Because the foliage is bitter and somewhat toxic, it is avoided by mammalian herbivores as a food source. Because its long leafy stems often form dense thicket tangles, Wild Sweet Potato provides excellent cover for birds and other kinds of wildlife during the summer and early fall.