- Name also: Common Stork’s-bill, Redstem Filaree, Redstem Stork’s Bill, Redstemmed Filaree, Coastal Heron’s Bill
- Family: Geranium Family – Geraniaceae
- Growing form: Annual or biennial herb. Taproot sparsely branched.
- Height: 5–50 cm (2–20 in.). With many stems, stem limp–ascending, abundantly branched, hairy.
- Flower: Regular or slightly unequal, approx. 10 mm (0.4 in.) broad. Petals 5, pink, sometimes dark-spotted at base, with entire tips, slightly different sizes (2 bigger than rest). Sepals 5, usually clearly shorter than petals. Stamens 10, some scale-like, without anthers. Pistil of 5 used carpels. Inflorescence a 3–8-flowered umbel, terminating stems and branches.
- Leaves: In basal rosette and on stem opposite. Blade narrowly triangular, feather-veined, pinnate; leaflets finely lobed.
- Fruit: 5-parted schizocarp, tip beak-like, coiling like a corkscrew as it dries. Mericarps smoothly haired.
- Habitat: Fields, gardens, yards, sandy areas, roadsides, harbours, rubbish tips.
- Flowering time: June–September(–October).
Common storksbill is an annual or biennial weed with a beautiful flower. The annual version’s stem is usually low and almost unbranched while the overwintering biennial version can grow to knee-height and is often very branched. Common storksbill resembles cranesbill, but it can be differentiated by e.g. its long, pinnately lobed leaves and slightly irregular corolla. The clearest difference is probably in the fruit: in common storksbill all five carpels break off and get distance from the stem when their long tips begins to curl like a corkscrew when they are ripe. The tip is sensitive to changes in humidity: in dry weather it curls tightly while in rain it straightens out. This movement can help the carpel bore down into the soil, and the corkscrew can attach itself to passing animals or people. Common storksbill’s efficient way of spreading explains why it grows almost worldwide, and it arrived in southern and especially eastern Finland in ancient times. It grows in gardens and yards, on arable land and by roadsides, especially in sandy places. New casual aliens have been found by harbours, near storehouses and beside railway tracks. These have reached their new habitats mixed up with e.g. grain.
Apart from common storksbill, musky storksbill grows rarely in the south-east of Finland. It can be differentiated from common storksbill by e.g. its ovate and large-toothed leaves, its purple flowers, and the glandular hairs on the beak of the fruit. A good identification marker is also the subtending bracts: common storksbill’s are fused, sharp-tipped and long-ciliate while musky storksbill’s are blunt and short-ciliate.