Raphanus raphanistrum, is a flowering plant in the family Brassicaceae. It is sometimes claimed to be the ancestor of the edible radish, Raphanus sativus. Native to western Asia, Europe and parts of Northern Africa. It has been introduced into most parts of the world and is regarded as a habitat threatening invasive species in many areas, for example, Australia. It spreads rapidly and is often found growing on roadsides or in other places where the ground has been disturbed.
Description
Wild radish grows as an annual or biennial plant, with a single taproot which is similar to that of the cultivated radish but less enlarged. It has basal leaves that are oblong-elliptic to spatula-shaped, the stem leaves are shorter and lobed. It has hairy stems and can grow to between tall. It blooms between May and September, in the UK, or between June and August, in the US. The flowers very similar to those of the searocket, which is found in some of the same regions and is easily distinguished from it by having thinner, non- stems and leaves. The stems have wide spaced, four-petalled flowers across and varying in colour, usually from white to purple but sometimes light orange to yellow, often with colour shading within a single petal. Later, on a short stalk, it produces a podded seed capsule. Up to 8 round jointed pods, each containing one round or oval seed.
Taxonomy
It was formally described by the Swedish botanist Carl Linnaeus in his seminal publication 'Species Plantarum' on page 669 in 1753. The genome of wild radish is estimated to be ~515 Mb. Approximately 49% of the genome has been sequenced. researchers found evidence of a past whole-genome triplication in wild radish followed by widespread gene loss, resulting in ~38,000 genes in the genome of the extant species. It has 3 known subspecies such as;
It has several common names including jointed charlock, jointed radish, jointed wild radish, sea radish, white charlock, and wild radish. It is often erroneously identified as mustard.
It is frost hardy, and even hard freezes only temporarily interrupt bloom. In Australia, it is regarded as a habitat threatening invasive species in many areas. In Canada, it is a naturalised species and sometimes hybridizes with cultivated radish, R. sativus. It has also proved to be resistant to several herbicides. In southeastern USA, the pale yellow form is common, sometimes entirely taking over fields in wintertime. It is a significant source of pollen and nectar for a variety of pollinators, especially honey bees during the very early spring starting buildup. Female Andrena agilissima,or mining bees, frequent this plant to obtain pollen and nectar. Other pollinators include cabbage butterflies and a few syrphid fly species.
