Tropaeolum majus (garden nasturtium, Indian cress, or monks cress) is a species of flowering plant in the family Tropaeolaceae, originating in the Andes from Bolivia north to Colombia. An easily-grown annual with disc-shaped leaves and brilliant orange or red flowers, it is of cultivated, probably hybrid origin. It is not closely related to the genus Nasturtium (which includes watercress).
It is a fast-growing plant, with trailing stems growing to 3–6 ft (0.91–1.83 m). The leaves are large, nearly circular, 3 to 15 centimeters (1.2 to 5.9 in) in diameter, green to glaucous green above, paler below; they are peltate, with the 5–30 cm long petiole near the middle of the leaf, with several veins radiating to the smoothly rounded or slightly lobed margin. The flowers are 2.5–6 cm diameter, with five petals, eight stamens, and a 2.5–3 cm long nectar spur at the rear; they vary from yellow to orange to red, frilled and often darker at the base of the petals. The fruit is 2 cm broad, three-segmented, each segment with a single large seed 1–1.5 cm long.
The garden nasturtium is used as a food plant by the larvae of some Lepidoptera species including the dot moth and the garden carpet moth. A common pest found on nasturtiums is the caterpillar of the large white or cabbage white butterfly.
The species has become naturalized in parts of the United States (California, New York, Pennsylvania, New Hampshire, Massachusetts, Connecticut and Virginia), as well as parts of Europe, such as Gibraltar, and Asia, Africa and Australia. It is also listed as invasive in Hawaii and Lord Howe Island, New Zealand.
