Scientific name: Rhamnus purshiana
Native American name:Chinook Tribe of Southwest Washington called it Chittam or Chitticum
Plant family: Rhamnaceae
Description: Rhamnus purshiana is a deciduous tree.
Its leaves are alternate, egg shaped, fine toothed and strongly pinnate. Its flowers are small, green to yellow colored with five petals. The berries are dark blue to dark purple and are edible.
Habitat and range: Cascara is found in dry or moist shaded woodlands as well as along stream and river banks. It is also commonly found in wetlands, in mixed forests with conifers as well as red alder and the vine maple. Cascara is native to the western part of North America, southern British Colombia, but can be found all along the PNW from central California up to southern BC and as far east as Montana.
Historical and contemporary uses: Rhamnus purshiana has been used for many centuriesor many centuries by many Native American tribes of the Pacific Northwest, such as the Nuxalk, Coastal Salish, Quileute, Nuu-chah-nulth, Kwakwaka’wakw and many others as a healing plant.
The main documented use for cascara is as a laxative. The bark can be stripped from the shrub and then made into a tea or as syrup, by boiling it. The bark is said to be too strong to be used fresh, so it must be dried for a year before it can be used as a laxative. Otherwise, the effect is too strong and it can cause severe nausea or diarrhea.
The Salish tribe would collect the bark in strips in the spring or summer and allow it to dry until the next summer. Once it was properly dried, they would then pound it into a pulp and afterwards, they would steep the pulp in cold water. Once it was steeped in the cold water, the water could then be boiled into a tea for drinking.
Drawings: http://en.wikipedia.org/wiki/File:Koeh-121.jpg and Elizabeth Sanner