T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network

Raphanus raphanistrum (Wild Radish)

Kingdom: Plantae
(Unranked): Angiosperms
(Unranked): Eudicots
(Unranked): Rosids
Order: Brassicales
Family: Brassicaceae
Genus: Raphanus
Species: R. raphanistrum 
Binomial name: Raphanus raphanistrum 
Common name: Wild Radish, Jointed Charlock

Raphanus raphanistrum is an annual or biennial flowering plant in the mustard family Brassicaceae. It is native to Eurasia. It has been naturalized throughout much of the world and is a noxious agricultural weed in many places. It became naturalised in New Zealand in 1854.
It starts out as a rosette of hairy leaves, with each leaf heavily lobed. When stem elongation occurs it forms an upright flower stem about 1 m tall, the stems and leaves remain bristly hairy.
It can spread rapidly and is often found growing on roadsides or in other places where the ground has been disturbed.
The four-petaled flowers (30–40 mm across) vary in colour due to genetic variability, but are usually pale yellow or white, and always with distinct purplish veins. There is often colour shading within a single petal. Raphanus raphanistrum blooms in early spring to late summer.
The fruits are borne below the flower head and are narrowly oval, jointed siliques containing 4 to 10 seeds.

A bank on New Plymouth's coastal walkway covered with Raphanus raphanistrum 

A young plant starts out as a rosette

A yellow-flowered variety 

More photos of colour variations below

The root system

The seed pods

The leaves.


Thanks to Wikipedia for text and information: