''Sisymbrium irio'', the London rocket, is a plant in the family

Brassicaceae Brassicaceae () or (the older) Cruciferae () is a medium-sized and economically important family of flowering plants commonly known as the mustards, the crucifers, or the cabbage family. Most are herbaceous plants, while some are shrubs. The leav ...

. It is an annual herb exceeding three feet in height with open, slender stem branches. The flowers are small with four pale yellow petals. The basal leaves are broad and often lobed, while the upper leaves are linear in shape and up to four inches long. The fruit is a long narrow cylindrical

silique A silique or siliqua (plural ''siliques'' or ''siliquae'') is a type of fruit (seed capsule) having two fused carpels with the length being more than three times the width. When the length is less than three times the width of the dried fruit i ...

which stays green when ripe. The younger pods overtop the flowers. When dried the fruit has small red oblong seeds. The term "London" in the common name "London rocket" allegedly comes from its abundance after the Great Fire of London in 1666. Plants and seed must have been present in London prior to the fire but generally overlooked until their abundant appearance after the fire;

Robert Morison Robert Morison (162010 November 1683) was a Scottish botanist and taxonomist. A forerunner of John Ray, he elucidated and developed the first systematic classification of plants.Vines Biography Born in Aberdeen, Morison was an outstanding ...

, the physician to King Charles II, attributed their appearance to

spontaneous generation Spontaneous generation is a superseded scientific theory that held that living creatures could arise from nonliving matter and that such processes were commonplace and regular. It was hypothesized that certain forms, such as fleas, could arise f ...

when he observed that “these hot bitter plants with four petals and pods were produced spontaneously without seed by the ashes of the fire mixed with salt and lime.” abey, Richard. "In Defence of Nature's Most Unloverd Plants." Chapter 10. HarperCollinsPublishers, 2010 In contrast, Dr E J Salisbury, in his study of the bombsites of London after the Great Fire of 1940, "failed to find a single specimen, nor has any other reliable observer reported it", according to R. S. R. Fitter. The term "Rocket" in the common name appears to be derived from the old Latin term "eruca" applied to several loosely-related plants in the cabbage family. abey, Richard. "In Defence of Nature's Most Unloverd Plants." Chapter 10. HarperCollinsPublishers, 2010 This species is considered a

weed A weed is a plant considered undesirable in a particular situation, "a plant in the wrong place", or a plant growing where it is not wanted.Harlan, J. R., & deWet, J. M. (1965). Some thoughts about weeds. ''Economic botany'', ''19''(1), 16-24. ...

in the Southwestern United States and other regions where it has been introduced.

Uses

The leaves, seeds, and flowers are edible, with a spicy flavor similar to cultivated

rocket A rocket (from it, rocchetto, , bobbin/spool) is a vehicle that uses jet propulsion to accelerate without using the surrounding air. A rocket engine produces thrust by reaction to exhaust expelled at high speed. Rocket engines work entirely fr ...

. London rocket is used in the

Middle East The Middle East ( ar, الشرق الأوسط, ISO 233: ) is a geopolitical region commonly encompassing Arabia (including the Arabian Peninsula and Bahrain), Asia Minor (Asian part of Turkey except Hatay Province), East Thrace (Europ ...

to treat coughs and chest congestion, to relieve rheumatism, to detoxify the liver and spleen, and to reduce swelling and clean wounds. The Bedouin use the leaf of London Rocket as a tobacco substitute. The cured pods can be placed in a basket with live coals and shaken until the pods are parched, then ground into meal and made into soup or stew.Warnock, Barton H. (1977) "Wildflowers of the Davis Mountains and the Marathon Basin, Texas", p. 111

Notes

References

* * Ray, Jarren ''et al.'' (2005) "Moisture and Temperature Requirements for London Rocket (''Sisymbrium irio'') Emergence" ''Weed Science'' 53(2): pp. 187–192 * irio Plants described in 1753 Taxa named by Carl Linnaeus Flora of Malta {{Brassicales-stub