Schisandra chinensis (五味子 in Chinese, pinyin: wǔ wèi zi, literally "five flavor berry") is a deciduous woody vine hardy to USDA Zone 4 and is dioecious, meaning individual plants are either male or female, thus both male and female plants must be grown if seeds are desired[citation needed]. It is very tolerant to shade. Its Chinese name comes from the fact that its berries possess all five basic flavors: salty, sweet, sour, pungent (spicy), and bitter. Sometimes it is specifically called in Chinese '北五味子' (pinyin: běi wǔ wèi zi, literally "northern five flavor berry") to distinguish it from another traditionally medicinal schisandraceous plant Kadsura japonica that grows only in subtropical berries are used in traditional Chinese medicine, where it is considered one of the 50 fundamental herbs. They are most often used in dried form, and boiled to make a tea. Medicinally it is used as a tonic and restorative adaptogen with notable clinically documented liver protecting effects. The primary hepatoprotective (liver protecting) and immuno-modulating constituents are the lignans schizandrin, deoxyschizandrin, gomisins, and pregomisin, which are found in the seeds of the fruit. It should not be used by pregnant women.