A brightly variegated cousin of the chaste tree, grown for foliage as much as flower. Vitex trifolia, sometimes called the three-leaf chaste tree or Arabian lilac, is a warm-climate shrub of the mint family, native along tropical and subtropical coasts from eastern Africa through southern Asia to Australia and the Pacific. The species name trifolia points to the leaves, usually held in threes, and the selection 'Variegata' edges each gray-green leaflet in creamy white for a cool, luminous effect.
John Bartram collected Xanthorhiza simplicissima from the Carolina mountains sometime before 1776 and brought the plant back to his famous Philadelphia garden, which tells you two things: that yellowroot has been in cultivation for as long as this country has existed, and that people who know plants have always recognized something worth paying attention to here. The Cherokee had known the plant far longer, using the roots, sliced open to reveal a vivid, almost electric chrome yellow, as a dye, a bitter tonic, and a medicine for ailments from mouth sores to stomach complaints. The active compound is berberine, the same antimicrobial alkaloid found in goldenseal, and the roots produce berberine in striking quantity. Xanthorhiza is Greek for yellow root, and the name is no metaphor.
A native tree that bites back, and can numb a toothache. Zanthoxylum clava-herculis, the toothache tree or Hercules' club, is a small to medium deciduous tree of the citrus family, native along the coastal Southeast from Virginia to Florida and Texas. The genus name Zanthoxylum means yellow wood, and the species clava-herculis, the club of Hercules, names the stout, spiny, club-shaped trunk that is the tree's signature.