Horse Nettle

Solanum carolinense

horse_nettle_12-21-13.jpg

Photo of horse nettle flowers and leaves
James H. Miller & Ted Bodner, Southern Weed Science Society, Bugwood.org
Thorny
Poisonous
Family

Solanaceae (nightshades)

Description

A native perennial with spiny stems and leaves; the fruits are toxic and look like tiny yellow tomatoes. Flowers in elongated clusters (racemes) at ends of stems, white to purple, about 1 inch across with 5 united petals, forming a five-pointed star with 5 large, yellow stamens protruding. Blooms May–October. Leaves with pointed lobes (somewhat resembling red oak leaves), with 4 lateral lobes and 1 shallow terminal lobe. Does not have bristles, but stems and midribs of leaves have yellow prickles. Fruit a smooth berry, yellow when ripe, like a tiny tomato, which persists through the winter. Most parts of the plant are toxic if eaten.

Size

Height: to 3 feet.

Horse nettle fruits

Horse nettle fruits in Osage Co
Horse nettle fruits
Horse nettle fruits in Osage Co
Habitat and conservation

Occurs in waste places, rights-of-way, openings in woods, fields, prairies, and other grassy or disturbed areas. To gardeners, it is a difficult-to-control weed, but it is also one of our native grassland wildflowers. The thick stands of grasses and forbs in our native prairies compete strongly with this plant, so in its native situation, horse nettle does not overwhelm its neighbors. Where soils are disturbed, horse nettle, lacking competition, grows profusely.

image of Horse Nettle distribution map
Distribution in Missouri

Statewide.

Status

Horse nettle is related to tomatoes and eggplant, whose fruits are edible because they contain a much greater percentage of carbohydrates, offsetting the presence of toxic alkaloids. Potato is also closely related, but it stores a large amount of carbohydrates in its tubers, rendering them edible. Horse nettle's fruits, however, don't store as many carbohydrates, so they contain a comparatively higher amount of the alkaloids, making them toxic to us.

Human connections

Horse nettle spreads easily by seed and by underground rhizomes and can be a troublesome weed, hard to pull for its spines and deep roots. Native Americans had medicinal uses for it, but all parts are toxic if eaten, and children have reportedly been killed by eating the fruit.

Ecosystem connections

Bumblebees pollinate the flowers, and a variety of insects (including predatory beetles that humans consider beneficial) feed on the leaves. Certain types of birds and some mammals eat seeds from mature fruit, but most mammals avoid them because of their toxic alkaloids.