This polyploid (2n = 88) is widespread across temperate regions of North America, usually on damp to marshy fertile alluvial soils. However, it is generally much reduced in highly agricultural regions, perhaps due especially to grazing. The common name of this species ("mad-dog skullcap") reflects its traditional use for treating rabies. Plants (especially roots) are known to contain the flavone "baicalein" and associated chemicals that can reduce anxiety; but they can also tranquillize or even induce mild paralysis (e.g. Awad et al. 2003). There is also much interest in anti-cancer potential. Other North American species of the genus appear to have been used much less, perhaps because they tend to be less robust or abundant; their chemistry remains largely unknown.