Rhamphospermum arvense

Charlock reaches on average in height, but under optimal conditions can exceed one metre. The stems are erect, branched or unbranched, striated, with coarse spreading hairs especially near the base. The leaves are petiolate (stalked) with a petiole. The basal leaves are oblong, oval, lanceolate, lyrate, pinnatifid to dentate, long, wide. The cauline leaves are much reduced and are short petiolate to sessile but not auriculate-clasping. It blooms from May to September, or May to August, in the UK. The inflorescence is a raceme made up of yellow flowers having four petals 6–13 mm long, with spreading sepals just over half the length of the petals. The fruit is a silique 2.5–5 cm long with a beak 0.7–2 cm long that is flattened-quadrangular. The valves of the silique are glabrous or rarely bristly, three to five nerved. The seeds are dark red or brown, The seeds contain a plant hormone, gibberellic acid, which effects the dormancy of the seeds. ==Taxonomy==

It was formally described by the Swedish botanist Carl Linnaeus in his seminal publication 'Species Plantarum' on page 668 in 1753. It is commonly known as charlock, or sometimes as charlock mustard, field mustard, or wild mustard. ==Distribution==

A native of the Mediterranean basin, from temperate regions of North Africa, Europe and parts of Asia. It has also become naturalised throughout much of North America, South America, Australia, Japan and South Africa. Range It is found in North Africa, within Algeria, Egypt, Libya, Morocco and Tunisia. Within Asia, it is found in Arabian Peninsula (in Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates), Armenia, Azerbaijan, the Caucasus, China, Georgia, Iran, Iraq, Israel, Jordan, Kazakhstan, Kyrgyzstan, Lebanon, Siberia, Syria, Tajikistan, Turkmenistan and Uzbekistan. It is also found in tropical Pakistan. In eastern Europe, it is found within Belarus, Estonia, Latvia, Lithuania, Moldova and Ukraine. In middle Europe, it is in Austria, Belgium, the Czech Republic, Germany, Hungary, the Netherlands, Poland, Slovakia and Switzerland. In northern Europe, in Denmark, Finland, Ireland, Norway, Sweden and the United Kingdom. In southeastern Europe, within Albania, Bosnia and Herzegovina, Bulgaria, Croatia, Greece, Italy, Montenegro, North Macedonia, Romania, Serbia and Slovenia. Also in southwestern Europe, it is found in France, Portugal and Spain. ==Habitat==

It grows in the plains and mountains, in pastures, fields, roadsides, waste places (such as railways, tips, and waste ground), and ruins, but mainly in cultivated places. It prefers calcareous soils in sunny places, at an altitude of above sea level. ==Ecology==

The flowers are pollinated by various bees like Andrena agilissima and flies (entomophily). Rhamphospermum arvense is the host plant of the caterpillars of some Lepidoptera, such as the small white, Pieris rapae. The seeds are toxic to most animals, except birds, and can cause gastrointestinal problems, especially if consumed in large quantities. It is a highly invasive species in states such as California. ==Uses==

Charlock leaves are edible at the juvenile stage of the plant; Once the seeds are ground, they produce a kind of mustard. A type of oil can be extracted from the seed which has been used for lubricating machinery. == As ruminant feed ==

Grazing charlock at growing and flowering stages is harmless for cattle and sheep. Poisoning can occur in the same animals when fed with older seed-bearing plants. This can occur when wild mustard grows as a weed in green-fed rapeseed or cereals. Accidental consumption of charlock oil can also be the cause of reported intoxications. Hôteur rabrouxhe efant.jpg|Plant more than 1 metre tall Gades ezès snés Djebel Xheder.jpg|Goats grazing in mountain pasture with charlock Tchamp plin d' siné dilé Feddala.jpg|Fallow dominated by charlock Siné grinnes mierplante.jpg|Individual mature plant Siné grinnes bohêye.jpg|Potentially toxic mature plants ==See also==