The bioregion known to some geographers as Cascadia corresponds to the Pacific Northwest and encompasses Southeast Alaska, British Columbia, Western Alberta and Montana, Idaho, Washington, Oregon and Northern California. It is a unique area that is home to a rich diversity of medicinal herbs and other plants, including Rhamnus purshiana, from which comes one of the more familiar herbs otherwise known as Cascara Sagrada Bark. In the original lingua franca of Cascadia, known as Tsinuk Wawa, or "Chinook Jargon," this Native American herb was called chittam or tsittikum.