Raphanus raphanistrum, also known as wild radish, white charlock or jointed charlock, is a flowering plant in the family Brassicaceae. The species is 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. The cultivated radish, widely used as a root vegetable, is sometimes considered to be one of its subspecies as Raphanus raphanistrum subsp. sativus.
Description
The petals have a characteristic pattern of veins
Wild radish is an annual that grows up to 75 centimetres (30 in) tall, variously branched to multi-stemmed, with a distinct slender taproot which does not swell like that of the cultivated radish. The stems are green and sometimes purple at the base and nodes, round in cross section and slightly ridged, and bristly-hairy all over. It has a basal rosette of pinnate leaves to 38 cm (15 in) long, with a 3-cm stalk (petiole) and a large rounded terminal lobe that has a undulate margin; the lateral lobes sometimes overlap the midrib. The stem leaves become progressively less lobed as they ascend, and more acutely serrated. Both the upper and lower surface of each leaf is roughly hairy, as are the leaf margins, which have minutely bulbous-based hairs projecting horizontally. The leaves have green or purple tips (hydathodes) on each tooth.
The basal leaves are often pinnately divided.
Habitat and distribution
The flowering period is between May and October in northern Europe, or between June and August in Minnesota. The inflorescence is a lax raceme, terminal or arising from the leaf axil, up to 34 cm long with up to 42 flowers. The flowers have four white (sometimes yellow or purple) petals, up to 24 mm long, sometimes with dark veins (especially on the underside). Each petal has a...