Erodium cheilanthifolium

Description

Erodium cicutarium, also known as redstem filaree, redstem stork's bill, common stork's-bill or pinweed, is a herbaceous annual – or in warm climates, biennial – member of the family Geraniaceae of flowering plants. It is native to Macaronesia, temperate Eurasia and north and northeast Africa, and was introduced to North America in the eighteenth century, where it has since become naturalized, particularly of the deserts and arid grasslands of the southwestern United States. The plant is widespread across North America. It grows as an annual in the continent's northern half. In the southern areas of North America, the plant tends to grow as a biennial with a more erect habit and with much larger leaves, flowers, and fruits. It flowers from May until August. Common stork's-bill can be found in bare, sandy, grassy places both inland and around the coasts. It is a food plant for the larvae of the brown argus butterfly. The seeds of this annual are a species collected by various species of harvester ants. It is a hairy, sticky annual. The stems bear bright pink flowers, which often have dark spots on the bases. The flowers are arranged in a loose cluster and have ten filaments – five of which are fertile – and five styles. The leaves are pinnate to pinnate-pinnatifid, with hairy stems. The long seed-pod, shaped like the bill of a stork, bursts open in a spiral when ripe, sending the seeds (which have long tails called awns) into the air. Seed dispersal behavior Erodium cicutarium seed uses self-dispersal mechanisms to spread away from the maternal plant and also to reach good germination site to increase fitness. Two techniques that Erodium uses are explosive dispersal, which launches seeds by storing elastic energy, and self-burial dispersal, where Erodium seeds move themselves across the soil using hygroscopically powered shape change.