The reference is to “poke sallet” and Tony Joe White's 1969 swamp rock hit "Polk Salad Annie." White — born July 23, 1943, Oak Grove, Louisiana, United States — is an American singer-songwriter and guitarist, best known for that song, https://www.youtube.com/watch?v=MCSsVvlj6YA
The plant, however, is quite interesting! It's native to the U.S. and flowers May-to-October. From Missouri Plants, http://www.missouriplants.com/Whitealt/Phytolacca_americana_page.html » “All parts of this weedy species are toxic when mature but the young shoots and leaves can be eaten when cooked. … The 'ink' from the berries will stain almost anything it touches.
“This is an easy species to ID in the field because of its big, alternate leaves, reddish stems, long inflorescences, and purple berries.”
Retired economics professor (“dismal scientist”). Married 40+ years to the love of my life; we have two grown daughters, both married, two granddaughters and a...