Yellow Wood Sorrel is one of my favorite plants to munch on! I love the sweet-sour taste of this plant. I may be a bit strange, but I love the leaves, the flowers and the seed buds.
This plant has been used for liver, digestion and even cancer cures. It is rumored, however, to adverse effects on the kidneys, but that has not dampened my enjoyment of this plant, and I'm rumored to have healthy organs (long story). First Nations have used and eaten this plant for thousands of years. In Druidic lore, this plant represents the common triune nature of the divine (maiden, mother, crone; youth, father, elder, etc.) and thus its equivalent european counterparts were considered sacred plants aligned with the triune.
Black Walnuts abound here. I have counted at least 20 such trees on my property alone. I gather these when they fall in late summer and keep them until the husks crumble, but before they sprout. By that time the nuts inside are mature and flavorful. This tree does not play well with many other plants, so if you want to cultivate them, make sure you know which plants can tolerate the chemicals this plant produces and keep your other plants far enough away to not be effected. Also, these are NOT good to have around horses or other herbivores and do not let your dogs chew on the nuts in their husk! These are commonly known to cause seizures and poisoning in dogs, mostly because they look like fun toys... The wood of this tree, however, is an excellent hardwood to use in building supplies, as long as you don't have wood chewing dogs.
An excerpt from an article from the purdue university http://www.agriculture.purdue.edu/fnr/HTIRC/pdf/woeste/KoleBookChapter-BlackWalnut-Pijut.pdf :
Historically, the bark of black walnut was used by several Native Americans, including the Cherokee,
Delaware, Iroquois, and Meskwaki, in tea as a cathartic, emetic, or disease remedy agent, and chewed or
applied for toothaches, snake bites, and headaches (Moerman 1998; Moerman 2003). Caution: the bark
should be used cautiously in medicine because it is poisonous. The Cherokee, Chippewa, and Meskwaki
also used the bark to make a dark brown or black dye (Moerman 1998; Moerman 2003). The Comanche
pulverized the leaves of black walnut for treatment of ringworm, the Cherokee used leaves to make a
green dye, and the Delaware used the leaves as an insecticide to dispel fleas (Moerman 1998; Moerman 2003)