Medicago polymorpha

Medicago polymorpha is a plant species of the genus Medicago. It is native to the Mediterranean basin but is found throughout the world. It forms a symbiotic relationship with the bacterium Sinorhizobium medicae, which is capable of nitrogen fixation. Common names include California burclover, toothed bur clover, toothed medick and burr medic. This weedy forb is an annual broadleaf plant. It inhabits agricultural land, roadsides and other disturbed areas. It is found in lawns as well, where its burrs are able to cling to the clothing or fur of any species that pass near it, thus facilitating geographic spread via these seed capsules. It makes a poor lawn in the late summer, when the leaves have yellowed and fruit sets into the 7 mm seed heads that are covered with hooked prickles. Burclover is a good forage for livestock, but the fruit is prickly. All classes of livestock, except horses and mules, can feed its leaves.