‘Kiss of Life’ saves extinct grass: Belgian endemic back for birthday celebrations

One of the world’s rarest grass species, the ‘Brome of the Ardennes’ (Bromus bromoideus) was until recently considered extinct. However, fresh, green shoots emerging from recently discovered seeds at the National Botanic Garden of Belgium, are causing quite a stir among European botanists in Belgium’s 175th anniversary of independence.

This species holds a particular interest to Belgians, since its world distribution was almost exclusively restricted to the calcareous meadows of the provinces of Liege and Luxembourg, with strongholds around Rochefort, Beauraing and the town of Comblain-au-Pont where it was first discovered in 1821. It soon became botanists’ most celebrated native plant and its engraving adorned the cover of many an edition of the ‘Belgian Flora’. In the latter part of the 18th Century, the species became rare and has been absent in the wild for the last 70 years. The reasons for its demise are attributed to changes in farming practices and the preoccupation of professional botanists with new floral riches arriving from Africa and the Americas. Fortunately, seeds were cultivated at the University Botanical Garden of Liege (now closed) from which seeds were distributed to a few other institutes. Over recent decades, however, many of these gardens have suffered the same fate as Liege and their plants long since gone.

I first became aware of the Brome’s infamous status while preparing for a European Native Seed Conservation Network (ENSCONET) meeting in Crete earlier this year. I was searching for examples of extinct Belgian species to illustrate a presentation. At first it seemed that nothing was left of the Brome, but on investigating further we discovered a handful preserved deep in the vaults of our seed bank. It was clear that I was probably looking at the last few remaining seeds of this species in existence.

We then checked with botanists in Belgium, France (where a small population of the grass was once recorded) and scoured the internet, to see if anyone else had the Brome seeds or plants. I came across one nursery in America that listed this species in their catalogue, but discovered upon contacting them that they had never actually had them in their collection. I suppose that if I had looked further down their list I might have found free-range Dodo eggs as well!

My investigations did reveal one small private collection of the Brome seeds in Flanders. These seeds, having been kept for 10 years in an attic, are unlikely to germinate. One of the purposes of the ENSCONET project is to determine the best techniques in seed preservation. Modern seed banking facilities are a vital tool for conservation, capable of preserving seeds over hundreds of years by carefully reducing their moisture content, and maintaining them at an astonishing minus 20°C. However, not all seeds act in the same way in storage – the only way to tell if they are still viable is to attempt to germinate them.

It was superb timing for this grass, as I happened to be Belgium’s representative for ENSCONET and was therefore able to consult with many of Europe’s top conservation biologists. He was able to benefit from the EU-funded network and establish links with the Millennium Seed Bank (MSB) of the Royal Botanic Gardens, Kew, in Britain, one of the world’s leading seed science research institutes. A small number of seeds were immediately dispatched to them and both institutes waited with baited breath to see if they could give this species the ‘kiss of life’.

On September 16th, I received the email he had been waiting for from Kew, confirming that the Meise seeds had successfully germinated. This also conveyed the information from Kew’s scientists about how best to incubate the precious remaining seeds.

“It was a relief to know that the garden’s seed bank was fulfilling its purpose and it illustrates the key role that botanic gardens have in conserving some of the world’s most vulnerable plant species,” said Thierry Vanderborght, seed bank manager at the National Botanic Garden of Belgium.

“This is one of the first successes of the recently formed conservation network across Europe funded by the EU. ENSCONET was formed last November and is headed by Kew’s Millennium Seed Bank team. Kew, the NBG Belgium and 17 other institutes from a dozen countries in Europe have joined forces to protect the continent’s most endangered species. Working together they can reduce duplication and improve data collection and management. This will be to the advantage of the many plants, such as Bromus bromoideus facing extinction”, said Simon Linington, head of curation at Kew’s Millennium Seed Bank.

The future of the ‘Brome of the Ardennes’, however, remains uncertain. We now believe the total number of viable seeds remaining to be fewer than 10,000, making this species one of the most threatened in the world. Of the total amount of seeds discovered in the bank less that 35% are viable, so it seems that time was indeed running out for this species. The best case scenario is for this species to be re-entered into the wild, although careful management will be needed to avoid a repeat of its decline.

Seedlings are now being grown at a secret location where it is hoped they will produce fresh seeds that can be bulked up and conserved in a variety of seed banks across Europe for safety and the long-term survival of Belgium’s most prized species.