Put the parsley, garlic, bay leaves, 3 lemon halves, the wine, olive oil and chicken broth in a large pot and bring to a simmer. Season with salt and pepper.
Meanwhile, prepare the artichokes: Wash the artichokes under cold water. Using a chef's knife, cut off the stems close to the base. Pull off the lower small tough leaves. Cut off the top inch of the artichoke and rub with the remaining lemon half to preserve the green color. (Alternatively, you may put the artichokes in acidulated water.) If you wish, trim the thorny tips of the leaves with kitchen shears.
Place the artichokes in the steaming liquid, bottom up. Cover and simmer until a knife inserted into the base meets no resistance, about 30 minutes.
Serve the steamed artichokes hot or cold with lemon wedges. To eat, pull off a leaf and dip in the melted butter; scrape the meat off the tender end with your front teeth. When you reach the center cone of prickly purple leaves, discard it (this is the choke that protects the heart). Now use a spoon to scrape away the thistle fuzz covering the heart, the meatiest part of the artichoke. Cut the heart into pieces and eat.