Redstem filaree is a member of the geranium family, Geraniaceae, which includes the bedding geranium (Pelargonium spp, as well as true geraniums (Geranium spp.) aka crane’s bills. Redstem filaree is also called common stork’s bill, redstem stork’s bill, and pin weed. It is native to the Mediterranean Basin but has naturalized in North America where it grows in disturbed areas such as lawns, fields, and roadsides and had become invasive in desserts and grasslands. In cool climates it is an annual but in warm climates it is a biennial.
A basal rosette of hairy pinnately lobed leaves produces successive layers of foliage with hairy red tinted stems one to twenty four inches long making large mats four to six inches in height. Loose clusters of two to eight purple pink flowers with five petals are produced in late winter to spring and are followed by seed capsules that resemble the head of a stork and contain a very large number of seeds. The seeds are released by a spring mechanism that also can cause the seeds to bury themselves in the ground. They germinate from spring until late summer and form a rosette which over winters. The root system is a taproot.
Hoe or hand pull the rosettes before they flower either in late fall, winter, or early spring, depending on the climate. For large areas a professional lawn specialist may be needed as the herbicides required to kill this weed are not available to ordinary citizens.