Nasturtium (literally "nose-twister" or "nose-tweaker"), as a common name, refers to a genus of roughly 80 species of annual and perennial herbaceous flowering plants in the genus Tropaeolum, one of three genera in the family Tropaeolaceae. It should not be confused with the Watercresses of the genus Nasturtium, of the Mustard family. The genus Tropaeolum, native to South and Central America, includes several very popular garden plants, the most commonly grown being T. majus, T. peregrinum and T. speciosum.
They have showy, often intensely bright flowers (the intense color can make macrophotography quite difficult), and rounded, peltate (shield-shaped) leaves with the petiole in the center. The flowers have five petals (sometimes more), a three-carpelled ovary, and a funnel-shaped nectar tube in the back.
The Nasturtiums receive their name from the fact that they produce an oil that is similar to that produced by Watercress (Nasturtium officinale), from the family Brassicaceae.
