Common stork’s-bill

Common stork’s-bill (Erodium cicutarium) certainly lives up to its name in respect of the first element, in that it is commonly found throughout Great Britain, particularly in gravel pits, dry grassland and on the margins of sandy beaches.

The plant grows up to 20 inches (50 centimetres) high, although some of the stems grow lengthways close to the ground. The leaves comprise double rows of leaflets of varying shapes.

Common stork’s-bill flowers from May to September, but each flower can be very short lived – appearing in the morning but dropping its petals by noon. The flowers are pink with the five petals longer than the sepals.

Common stork’s-bill is notable for the extraordinary method it has of propagating its seeds. Each fruit has five narrow segments that together form the “stork’s-bill” of the second element of the plant’s name. When the seed is ripe, the “bill” twists at the base and the five seeds are released, each at the end of a corkscrew-like filament.

When the seed falls the corkscrew is still attached, and this then tightens or loosens with variations in humidity. The effect is that the corkscrew buries itself in the ground, taking the seed with it. There are backward-pointing hairs on the stem that prevent the seed from re-emerging from the soil. When the seed is at the correct depth for germination the corkscrew ceases to operate.

© John Welford