Melampyrum pratense or Common Cow-wheat is a plant species of the genus Melampyrum

Melampyrum

Melampyrum is a genus of about 10-20 species of herbaceous flowering plants in the family Orobanchaceae, native to temperate regions of the Northern Hemisphere...

. This plant has an interesting relationship with ant

Ant

Ants are social insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from wasp-like ancestors in the mid-Cretaceous period between 110 and 130 million years ago and diversified after the rise of flowering plants. More than...

s. It produces a sugary liquid from small glands under its petals, which wood ants feed on. The seed

Seed

A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...

s of this plant have evolved to mimic the cocoons of wood ants, which are crucial in their dispersal

Biological dispersal

Biological dispersal refers to species movement away from an existing population or away from the parent organism. Through simply moving from one habitat patch to another, the dispersal of an individual has consequences not only for individual fitness, but also for population dynamics, population...

, transporting the seeds into their nests.. The plant is an Ancient Woodland

Ancient woodland

Ancient woodland is a term used in the United Kingdom to refer specifically to woodland that has existed continuously since 1600 or before in England and Wales . Before those dates, planting of new woodland was uncommon, so a wood present in 1600 was likely to have developed naturally...

indicator as the ants rarely carry the seeds more than a few yards, seldom crossing a field to go to a new woodland. It has been suggested that the species of ant that does this may now be extinct.