Virginia Tech Weed Identification Guide

Horsenettle: Solanum carolinense

Weed Description:  A perennial from rhizomes with conspicuous spines on the leaves and stems that may reach 3 ft in height.  Horsenettle is found throughout the southeastern, eastern, and north-central United States.  All parts of the plant, except the mature fruit, are poisonous to livestock even when this weed is consumed in dry hay.  However, consumption of this weed rarely occurs due to the prickly stems and leaves.
Seedling: Cotyledons oblong, glossy green above, light green below with hairs on the margins.  Short, stiff hairs cover the hypocotyl, which is often purple-tinged.

Leaves:  Simple, elliptic-oblong to oval, alternate, petioled, 2 1/2-4 1/2 inches long and covered on both surfaces with star-shaped hairs.  Leaves also emit a potato odor when crushed, and contain prominent prickles (6-12 mm long) on the midvein and petiole.

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Roots:  Deep, spreading rhizomes.

Flowers:  Occur in clusters on prickly flower stalks and are star-shaped with 5 white to violet petals and a yellow cone-shaped center, which is actually 5 stamens with yellow anthers.

Fruit:  A berry, 1/2-3/4 inches in diameter, green when immature turning yellow and wrinkled with maturity.  A single berry may contain from 40 to 120 seed.
Stems:  Angled at the nodes, become woody with age, and also have prickles and star-shaped hairs.
Identifying Characteristics:   Stems and leaves with prickles and star-shaped hairs. Horsenettle might be confused with other solanaceous species like Clammy Groundcherry (Physalis heterophylla). However, groundcherries do not have prickles on the stems and leaves and have papery membranes enclosing their berries. horsenettle9-10.jpg (87341 bytes)