A genus of dicotyledonous (see dicotyledon) herbs, often succulent. Many species climb by means of twining leaf stalks. The leaves may be entire or palmately lobed, with long stalks. The flowers are showy, with 5 irregular petals, and 5 sepals forming a spur below. T. majus is the nasturtium, a common garden ornamental from S. America, once cultivated as a salad plant. There are 86 species, occurring from Mexico to Patagonia.
Subjects: Plant Sciences and Forestry.