Tradescantia is a genus of about 70 species of flowering perennial plants, commonly called the spiderworts. Other common names of Tradescantia species include cradle-lily, flowering inch plant, oyster-plant, and spider-lily. They are native to parts of North, Central, and South America, ranging from southern Canada to northern Argentina. The plant takes its name from two 17th century English naturalists, father and son, named John Tradescant.
Tradescantia usually feature bright blue, three-petaled flowers with six yellow anthers, though some species have white, pink, or purple flowers. In many species, the flowers open in the morning and close in the afternoon. The plant is sometimes considered a weed, though it is also cultivated as both a garden plant and a potted plant. It is popular as a border plant in gardens.
Tradescantia virginiana, or Virginia spiderwort, was the first Tradescantia species described. It is native to the eastern United States, as well as southern Ontario, Canada. T. virginiana was introduced to Europe in 1629 and has been cultivated as a garden plant ever since. T. ohiensis is the most common Tradescantia species growing in the wild in the United States. It shares much of its range with T. virginiana, but also extends west to Texas and Kansas.
Three species of Tradescantia, T. fluminensis, T. pallida, and T. zebrina, share the common name Wandering Jew, after a character of Christian folklore. All three species have the tendency to become invasive species, but they are also cultivated as houseplants. T. fluminensis is native to South America, while T. pallida and T. zebrina are both native to Mexico.
T. fluminensis has white flowers, and T. zebrina has magenta flowers and distinctive sliver stripes on its leaves. T. pallida, sometimes called Purple Heart or Purple Queen after the color of its leaves and flowers, can improve indoor air quality when kept as a houseplant. T. pallida sometimes has white or pink flowers. The watery sap of T. zebrina can cause skin irritation, though the plant is also used to make an herbal tea called Matali in the Tabasco region of Mexico.
Some Tradescantia plants, including T. occidentalis or the Western spiderwort, feature flowers with blue stamen hairs. In the presence of ionizing radiation, such as gamma rays or neutron radiation, the stamen hairs become pink as a result of their cells mutating. Therefore, spiderwort species with this feature can be used to identify radiation in an environment.