Field cow-wheat (Melampyrum arvense) is a striking plant, sending up bright purple sprays of flowers in the summer. It is part of the broomrape family, a group of plants that specialise in parasitizing other plants so successfully that some of them don’t even bother putting out leaves. Field cow-wheat is itself a hemi-parasite, meaning that it gets some of its food from regular photosynthesis and some of it from the roots of its neighbours – favouring grasses.

It used to be a common sight along arable margins and within the fields, where it was considered a weed, but is now absent across much of its former habitat where newer agricultural practises have wiped it out. There is also an understudied link between its large, poisonous seeds and ants. On chalk sites and other biodiverse regions, it’s thought that ants carry the seeds away from the parent plant and spread it a short way, perhaps lured by a tasty outer coating or an intriguing pheromone. On newer sites without established ant colonies, the heavy seeds can form little pyramids right at the base of the parent plant. 

Field cow-wheat is an annual, which means each plant only lives one year and it needs to shed its seeds for the next generation to grow. If one year’s population is wiped out, it probably won’t reappear the next year as the seeds can’t stay dormant in the soil for long.

Species re-introduction: a process of trial and error

On Coombe Bissett, in the heart of the restricted fields, there are three small plots where this precious plant has been introduced. This project is led by Dominic Price of the Species Recovery Trust, and the plants are carefully monitored over the year to see how they are getting on. When these plots were established a few years ago, not much was known about what it takes for them to thrive, and it’s definitely been a bit of trial and error! 

Cow-wheat is a fickle plant – it likes a light, open sward typical of chalk grasslands, but doesn’t respond well to the grazing necessary to keep that sward open. Its delicate roots spend much of the winter very close to the surface of the soil, where they hate getting trampled, and in the summer, cows love to break in and nip off the young plants despite the fencing! – where the plots were unfenced it seems to have disappeared entirely. As a plant of arable fields and old hay meadows, it does much better with an October hay cut, and the learning curve seems to show that despite the huge diversity present on a site like Coombe Bissett, the field cow-wheat would really rather be somewhere else…

But that’s what science is about! With this information, the new sites chosen for field cow-wheat are much more suitable for its needs, with a large-scale seeding initiative being planned to give this species the resilience needed to survive. And despite its drawbacks the cow-wheat at Coombe is still there, still flowering, still surviving.

Resilient seedlings, flowers in bloom and a hopeful future

In April, Dom and I counted around 215 tiny little seedlings, most no bigger than a thimble. Since then we’ve had heatwaves, two break-ins from the cows, and so little rain that there were genuine doubts that any of them would survive. We went back up at the end of June, as part of a joint Grassland ID course with the RSPB, to count them.

Put eight conservationists in a field and you’ll get nine different answers, but the outcome was very positive indeed:

58 adult plants. Many of them very large with multiple flowering stems in bright, printer-ink magenta, some of them yet to flower and still a soft grey-green with their lance-like leaves. Not only that, but they’ve spread out from their original plot where they were seeded, possibly carried uphill by those ants that scurry all over the reserve. This marks the fourth year of this population maintaining itself with no outside influence, from very humble beginnings in a tiny plot only a couple of metres square.

And if the field cow-wheat can thrive here, not in ideal conditions, vulnerable to weather and hungry animals and the sheer low numbers of its population, then imagine how it must now be thriving elsewhere. Hope is not lost for this little plant, and we hope to one day see it again in our field margins and hay meadows as a welcome, but common, yearly spray of colour.