Blue-hearts? They always look a little more purple to me. Either way, they are hemiparasites. Sometimes sap suckers, and sometimes not. If they find the right tree roots to fasten to, they become larger and more plentiful, but they can do well enough by themselves. Except maybe here in Michigan, where they have not been recorded since 1838. They have been found in AL, AR, DE, FL, GA, IL, IN(E), KS, KY, LA, MD(X), MI(X), MO, MS, NC, NJ, NY(E), OH(T), OK, PA(X), SC, TN, TX, VA, and ON(E). Wakulla Co FL, 7/8/18. Broomrape family, Orobanchaceae.