Sansevieria trifasciata

Sansevieria trifasciata is a species of flowering plant in the family Asparagaceae, native to tropical West Africa from Nigeria east to the Congo. It is most commonly known as the snake plant, Saint George's sword, mother-in-law's tongue, and viper's bowstring hemp, among other names. It is an evergreen perennial plant forming dense stands, spreading by way of its creeping rhizome, which is sometimes above ground, sometimes underground. Its stiff leaves grow vertically from a basal rosette. Mature leaves are dark green with light gray-green cross-banding and usually range from 70–90 centimetres (28–35 in) long and 5–6 centimetres (2.0–2.4 in) wide, though it can reach heights above 2 m (6 ft) in optimal conditions. The specific epithet trifasciata means 'three bundles'. The plant exchanges oxygen and carbon dioxide using the crassulacean acid metabolism process, which is only present in a small number of plant species. It allows them to withstand drought. The microscopic pores on the plant's leaves, called the stomata and used to exchange gases, are only opened at night to prevent water from escaping via evaporation in the hot sun. As a result, stored oxygen is released at the opening of the stomata at night, unlike most plants which continuously exchange gases during the day. It is a weed in some parts of northern Australia. Sansevieria trifasciata is commonly called 'mother-in-law's tongue', 'Saint George's sword' or 'snake plant', because of the shape and sharp margins of its leaves. It is also known as the 'viper's bowstring hemp', because it is one of the sources for plant fibers used to make bowstrings. It is known as hǔwěilán (虎尾兰 or 虎尾蘭, 'tiger's tail orchid') in China; tora no o (とらのお, 'tiger's tail') in Japan; and paşa kılıcı ('pasha's sword') in Turkey. In Portugal and Brazil, it is known as espada de São Jorge ('sword of Saint George'). In the Netherlands and Flanders (Belgium), the plant is also known as 'vrouwentong' (women's tongue). In Russia it is known as 'тёщин язык' ('mother-in-law's tongue') and 'щучий хвост' ('pike's tail'). Like some other members of its genus, S. trifasciata yields bowstring hemp, a strong plant fiber once used to make bowstrings.