It is a fast-growing plant, either
annual or
perennial, with trailing stems growing to . The
leaves are large, nearly circular, 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 in diameter, mildly scented, with five petals, eight stamens, and a 2.5–3-cm-long nectar spur at the rear. The petals vary from yellow to orange to red, frilled and often darker at the base. The fruit is 2 cm broad, three-segmented, each segment with a single large seed 1–1.5 cm long.
Unique effects Nasturtium leaves, like some other species, demonstrate the
lotus effect, whereby rainwater falling on the surface gathers into globular droplets which roll off the leaf, leaving it dry and clean.
Das Elisabeth Linné-Phänomen (the Elizabeth Linnæus Phenomenon), named after
Carl Linnaeus's daughter
Elisabeth Christina von Linné (who discovered the phenomenon at age 19) refers to the appearance of 'flashing' flowers. Especially at dusk, the orange flowers may appear to emit small flashes. Once believed to be an electrical effect, it is today thought to be an optical reaction in the human eye caused by the contrast between the orange flowers and the surrounding green. == Etymology ==