Carolina horsenettle
A prickly perennial weed native to North America, naturalized in Japan. The name literally means 'bad eggplant'.
Carolina horsenettle has thorns, so please don't touch it with bare hands.
Kanji spelling is rare and mainly used in botanical contexts; learners will almost always encounter the katakana form.
The Japanese name ワルナスビ (悪茄子) literally means 'bad eggplant', referring to its resemblance to eggplant and its thorny, weedy nature. The exact origin of the name is uncertain, but it likely arose from its undesirable characteristics.