CHARLOCK

Sinapis arvensis

Cabbage Family [Brassicaceae]

month8apr month8april month8may month8jun month8june month8jul month8july month8aug month8sep month8sept month8oct month8nov

status
statusZarchaeophyte
flower
flower8yellow
morph
morph8actino
petals
petalsZ4
type
typeZclustered
stem
stem8round
stem
stem8ribbed

12th May 2010, Staveley, Chesterfield Canal under re-construction. Photo: © RWD
Grows up to 1m tall, but usually only half that height.


Photo: © RWD
These two plants (above photo and this one) may look quite dissimilar with respect to the shape and size of the leaves, but the leaves of Charlock are possibly the most variable of any plant in the Brassicaceae family. Most botanists secure the ID by studying the shape and size of the pods, but here, on both plants, any pods visible are thin because of immaturity. But ID here confirmed by the expert on Crucifers in the country: Tim Rich himself.


12th May 2010, Staveley, Chesterfield Canal under re-construction. Photo: © RWD
Flowers bright-yellow. Stems may be dark-purplish if the plant is sun-stressed. Upper stem leaves may (or may not) have a pair of lobes closest the stem.


12th May 2010, Staveley, Chesterfield Canal under re-construction. Photo: © RWD
Flowers 15-20mm across. The flower buds closest to the tops are smaller than those of Winter-cress(es) and less green. Upper leaves smaller and usually un-stalked or with a short stalk (petiole) 5 or 10mm long.


12th May 2010, Staveley, Chesterfield Canal under re-construction. Photo: © RWD
Leaves matt and either toothed, or irregularly toothed - usually with prickly bristles.


Photo: © RWD
Lower leaves are stalked and may be pinnately lobed, as exhibited classically by the leaf in the centre of the lower right quadrant.


Photo: © RWD
Other weeds lower left. Flowers un-like those of Winter-cress(es) which fold-over after emerging from cupped sepals; on Charlock they are spread out and paddle-shaped; not at all contained by the sepals.


Photo: © RWD
Text goes here


23rd July 2005 Leeds & Liverpool Canal, Nelson, Lancs. Photo: © RWD
ID of these two Nelson photos not confirmed, but probably Charlock on account of the leaves, the petals and the sepals. Immature pods top right. (With a tiny white-flowered Bedstraw interloper).


23rd July 2005 Leeds & Liverpool Canal, Nelson, Lancs. Photo: © RWD
Four narrow sepals, here spread out (as on half of Charlock plants) and the petals are paddle-shaped and not constrained by the sepals.


Photo: © RWD
Lower leaves toothed or irregularly toothed, lobed or un-lobed.


Easily mistaken for : several other yellow-flowered Crucifers.

Many similarities to : Chinese Mustard (Brassica juncea) which differs most in the sepals and in the seed-pods but which occurs in far fewer places.

Some similarities to : White Mustard (Sinapis alba) a yellow-flowered plant, despite the name, but that upper leaves which are both stalked and pinnately lobed.

Slight resemblance to : Black Mustard (Brassica nigra) but that has a long upper stem of seed-pods which are appressed to the stem.

An archaeopyte which grows in the field borders of arable fields, waste land, land-fill sites, roadsides and other disturbed land, occurring throughout the British Isles.

There are 6 stamens with yellow anthers and the stigma is entire to emarginate.

SINALBIN, A GLUCOSINOLATE

The seeds are poisonous to all but birds. However the young leaves, although hot, may be eaten with a salad. Like many Brassicaceae the plant contains toxic glucosinolates, and in Charlock, one of these is Sinalbin, named after the Genus Sinapis.



Sinalbin is a glucosinolate which was first found in the seeds of White Mustard (Sinapis alba) and also occurs in Charlock and many other brassicas. Note that it seems to be rare in the world of secondary metabolites in containing a sulfate ion. Sinalbin is degraded by the enzyme myrosinase into the highly unstable and pungent mustard oil 4-hydroxybenzyl isothiocyanate (not shown), which has a half life of only 1 to 2 hours in the stomach. 4-hydroxybenzyl isothiocyanate itself degrades to the relatively odourless 4-hydroxybenzyl alcohol called Gastrodigenin (found as is in the rhizome of the plant Gastrodia elata, an orchid found in the Far East) plus a thiocyanate ion, the poisonous element.


Photos required of mature pods showing their beak and and close-up of flowers showing the narrow sepals either spread-out sepals or slightly down-turned, as is found on only half the plants (the other half have patent sepals [upright])


  Sinapis arvensis  ⇐ Global Aspect ⇒ Brassicaceae  

Distribution
 family8Cabbage family8Brassicaceae

 BSBI maps
genus8Sinapis
Sinapis
(Mustards)

CHARLOCK

Sinapis arvensis

Cabbage Family [Brassicaceae]