Solanum carolinense /Nightshade Family
Horsenettle is a member of the Nightshade family and is a thorny relative of the tomato. The small, poisonous yellow fruits look and smell like tomatoes. The unripe fruit and leaves are poisonous to humans (although, you'd have to be starving to death to want to eat the thorny leaves!), rodents, goats, cattle, sheep, and horses. The toxins contained in the leaves are soladulcidine and solanine.
Where seen: Oak Ridge, Great Smoky Mountains NP, Warrior's Path SP, widespread