Sow Thistle

Black nightshade (Solanum nigrum) is a significant weed in arable and horticultural crops but it is also common in disturbed pasture. Black nightshade is present throughout New Zealand but less so in the lower South Island. Distinctive black berries (7-10 mm) can be found on mature plants.

Storksbill (Erodium cicutarium) is an invasive, sticky, hairy plant which grows in rossetes up to 30 cm across. It is widespread throughout New Zealand in drier coastal and lowland areas, and found in pasture, grassland and arable land. The leaves are pinnate, resemble ferns, and are divided into pairs of leaflets. The flowers are a mauve-pink colour, have five undivided petals, and are arranged in loose clusters on reddish coloured hairy stalks. Flowering is September to May.

The seeds are contained in a long seed-pod which resembles the bill of a stork. When ripe the seed-pod bursts open into five strips, launching the seeds like little parachutes, or by means of the strips which have seeds attached to them, burying themselves into loose soil.

Speedwell (Veronica persica) is very common throughout New Zealand. Also known as scrambling speedwell, it is a sprawling, many stemmed annual with blue flowers. Germinates in both autumn and spring, so can be a problem weed in arable and brassica crops.