Melampyrum pratense or Common Cow-wheat is a plant species of the genus Melampyrum. This plant has an interesting relationship with ants. It produces a sugary liquid from small glands under its petals, which wood ants feed on. The seeds of this plant have evolved to mimic the cocoons of wood ants, which are crucial in their dispersal, transporting the seeds into their nests. The plant is an Ancient Woodland indicator as the ants rarely carry the seeds more than a few yards, seldom crossing a field to goto a new woodland. It has been suggested that the species of ant that does this may now be extinct.