Barbarea - Winter-cress

Barbarea have clasping upper stem leaves, dark-green, shiny pinnate lower leaves. They have fruits with single row of seeds and short persistent styles.

while the family can be identified by leaves, but it is much easier to distinguish them by the fruits.

Firstly, the position the fruits are held with respect to the stem and.the width of the stalk compared to the fruit.

Secondly, the fruits all have persistent styles at the end, from the flowers, and the size and shape styles of these are important.

Barbarea vulgaris - Winter-cress

This is the commonest.

The persistent styles are thin and 2 – 3.5mm long and the fruit 1.5 – 3 cm and pressed to stem.

Uppermost stem-leaves simple, toothed or lobed less than halfway to midrib (ignore basal lobes).

Barbarea intermedia - Medium-flowered Winter-cress

Persistent styles are shorter, stout, 0.6 – 2mm long, fruit pressed to the stem, 1.5-3.5( 4) cm.

Uppermost stem-leaves ± pinnate to pinnately lobed more than halfway to midrib.

Barbarea verna - American Winter-cress

Persistent styles are shorter, stout and 0.6 – 2mm long, fruits are much longer 3.5 – 7cm and gently curved upwards and held away from the stem.

Uppermost stem-leaves ± pinnate to pinnately lobed more than halfway to midrib.

Apparently, the other two have leaves that taste foul, whereas this is like water-cress.