|Flower and foliage|
Tropaeolum majus (garden nasturtium, Indian cress or monks cress) is a flowering plant in the family Tropaeolaceae, originating in the Andes from Bolivia north to Colombia. It is of cultivated, probably hybrid origin, with possible parent species including T. minus, T. moritzianum, T. peltophorum, and T. peregrinum. It is not closely related to the genus Nasturtium (which includes watercress).
It is a herbaceous annual plant with trailing stems growing to 1 metre (3 ft 3 in) long or more. The leaves are large, nearly circular, 3 to 15 centimetres (1.2 to 5.9 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.
Das Elisabeth Linné-Phänomen
Das Elisabeth Linné-Phänomen, or the Elizabeth Linnæus Phenomenon, is the name given to the phenomenon of "Flashing Flowers". Especially at dawn, the orange flowers may appear to emit small "flashes". Once believed to be an electrical phenomenon, 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. The phenomenon is named after Elisabeth Christina von Linné, one of Carl Linnaeus's daughters, who discovered it at age 19.
Cultivation and uses
Garden nasturtiums are grown for their flowers, and also because both their leaves and flowers are edible; they can be used in salads, imparting a delicately peppery taste. The seeds are also edible, and can be used as a caper substitute.
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 very common "pest" found on nasturtiums is the caterpillar of the Large White (Cabbage White) Butterfly.
Nasturtiums are also considered widely useful companion plants. They repel a great many cucurbit pests, like squash bugs, cucumber beetles, and several caterpillars. They have a similar range of benefits for brassica plants, especially broccoli and cauliflower. They also serve as a trap crop against black fly aphids. They also attract beneficial predatory insects.
- Germplasm Resources Information Network: Tropaeolum majus
- Huxley, A., ed. (1992). New RHS Dictionary of Gardening. Macmillan ISBN 0-333-47494-5.
- Jepson Flora: Tropaeolum majus
- Pacific Island Ecosystems at Risk: Tropaeolum majus
- H. W. "Das Elisabeth Linné-Phänomen (sogenanntes Blitzen der Blüten) und seine Deutungen", Nature (nature.com). Retrieved 4 May 2013.
- "Försenad jätteplantering till Malmös schlagerfest, expert varnar för kalkning och kogödsel på påse", Odla med P1, Sveriges Radio, 29 April 2013. Retrieved 4 May 2013. (in Swedish)
- Plants For A Future: Tropaeolum majus
- See California Invasive Plant Inventory (As of July 2010) on line
- "Dot Moth - Melanchra persicariae". Recording the wildlife of Leicestershire and Rutland. NatureSpot. Retrieved 2012-06-21.
- Plymley, Katherine. "Garden Carpet Moth and Caterpillar Xanthorhoe fluctuata, Nasturtium". Shrewsbury Museums Service. Retrieved 2012-06-21.
- "Cabbage caterpillars". Royal Horticultural Society. 2011-02-22. Retrieved 2012-06-21.