I don't know about where you live, but there is still some nice autumn color here in Boston. The leaves on the oaks in my neighborhood are tuning dark red, and the Norway maples are bright yellow.
I found this colorful viney shrub on a neighborhood perambulation. The plant is called bittersweet, and its branches are often used for autumn wreaths and centerpieces. Maybe you'll see some bittersweet adorning the place you eat your Thanksgiving dinner this year.
There are a few types of bittersweet, including an invasive species from Asia (which is what I found) and a species native to North America. According to the folklorist Clara Kern Bayliss, people in Vermont believed that the root of the bittersweet plant provided protection against evil witches and malevolent magic. However, certain conditions applied to collecting the root. You couldn't just go out and start digging.
Bayliss notes that a doctor in Shaftsbury would go with his wife and daughter on a certain day of the year to collect bittersweet root to ward off witches. The doctor and his family would not talk, or look from side to side, from the moment they left their house until they returned.
Unfortunately Bayliss doesn't indicate on what day of the year they would collect the root. Was it the same day every year, or did it change depending on the weather or other criteria? I'd love to know.
It's not surprising they gathered the plant in silence. Silence is an important ingredient in some folk magic, and speaking often breaks a spell. For example, you can control a witch with their own witch bridle if you throw it over their head, but they will be freed as soon as you speak a word. Somehow silence was important to maintain the efficacy of the bittersweet.
There is a third plant sometimes called bittersweet, the bittersweet nightshade. This is a weedy invasive import from Europe with poisonous berries and toxic leaves. Leave this one alone!
Special note to my Wiccan and witchy readers: New Englanders wanted protection from witches who practiced maleficium, or harmful magic. Other than the very religious, most people didn't shun magic or fortune-telling. I don't want anyone to get offended by all this negative talk about witches!
I got my information from Clara Kern Bayliss's 1908 article, "Witchcraft", which appeared in The Journal of American Folklore.