Low, woody, and built to sprawl. Groundcover shrubs bring the permanence and structure of woody plants down to ankle height, covering ground with evergreen substance where a soft perennial carpet would thin or die back.
A tough, salt-defying seaside groundcover with a serious caveat. Vitex rotundifolia, best known as beach vitex, is a low, prostrate, trailing shrub of the mint family, native to the coasts of eastern Asia, the Pacific islands, and Australia, where the plant binds shifting sand along the shore. Rounded, blue-green leaves about two inches across clothe the running stems, aromatic and slightly spicy when crushed, and spikes of bright lavender-blue flowers open in late summer.
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.
