I took this photo in Virginia this week. I like the yellow stamens, and think they very much resemble a bunch of miniature bananas.
This one is growing next to a fire station close to where I am staying in Virginia. I had a hard time identifying it because I was certain it belonged to the Physalis genus (strawberry tomatoes, tomatillos). Check out the similarity:
Right family, wrong genus. The most obvious difference is the color of the flowers, but I understand they can sometimes be yellow in horsenettle.
The family itself is Solanaceae, which contains a mix of highly poisonous (nightshade) and quite edible (tomato, potato, tomatillo) plants. All members have poisonous parts due to the presence of solanine (which was named after this family). Solanine is an alkaloid, and the plant uses this as its primary defense against fungi and pests. Wikipedia has this to say about it:
Solanine poisoning is primarily displayed by gastrointestinal and neurological disorders. Symptoms include nausea, diarrhea, vomiting, stomach cramps, burning of the throat, cardiac dysrhythmia, nightmare, headache and dizziness. In more severe cases, hallucinations, loss of sensation, paralysis, fever, jaundice, dilated pupils, hypothermia and death have been reported.