Tragopogon porrifolius is a plant cultivated for its ornamental flower, edible root, and herbal properties. It also grows wild in many places and is one of the most widely known species of the salsify genus, Tragopogon. It is commonly known as purple or common salsify, oyster plant, vegetable oyster, Jerusalem star, goatsbeard or simply salsify (although these last two names are also applied to other species, as well).
T. porrifolius is a common biennial wildflower, native to Mediterranean regions of Europe but introduced elsewhere, for example, into Great Britain, (mainly in the south) and northern Europe, North America, and southern Africa and in Australia; in the United States it is now found growing wild in almost every state, including Hawaii, except in the extreme south-east.
The plant grows to around 120 cm in height. As with other Tragopogons, its stem is largely unbranched, and the leaves are somewhat grasslike. It exudes a milky juice from the stems.
The root is noted for tasting of oysters, from which the plant derives its alternative name of oyster plant; young roots can be grated for use in salads, but older roots are better cooked, and they are usually used in soups or stews. It is recommended that when using the root that, if cut, its color be preserved in acidulated water. A latex derived from the root can be used as a chewing gum. The flowering shoots can be used like asparagus, either raw or cooked, and the flowers can be added to salad, while the sprouted seeds can be used in salads or sandwiches.
The plant has also been used in herbalism, also since classical times (it is mentioned by Dioscorides), and is claimed to have beneficial effects on the liver and gall bladder. The root is regarded as a diuretic.