Astragalus berytheus (Fig. 1) is a plant from the Fabaceae (legumes) family, with a narrow range restricted to the eastern Mediterranean coast of Lebanon and Palestine/Israel (Fig. 2). It was discovered by the famous naturalists Pierre Edmond Boissier and Charles Isidore Blanche in the 17th Century. Astragalus berytheus is a biannual plant with discrete reddish flowers that appear in March. It bears beautiful red hairy pods that release their seeds in May. Many of the Lebanese populations of this rare plant collapsed when its habitat—sand dunes—were destroyed in 1997 as a result of the construction of Beirut airport and the highway connecting Beirut to southern Lebanon (Fig. 3).

Fig. 1 (left): Astragalus berytheus endemic to the eastern Mediterranean coast. Fig. 2 (right): The present and historical distribution of A. berytheus.

The only remaining population in Beirut was in Jnah-Ramlet El Baida-Beirut, but this also vanished, in 2015, when it was buried under construction rubble. Today, the only population of A. berytheus remaining in Lebanon is in Tyre Nature Reserve. And even there it was recently threatened by camphorweed Heterotecha subaxillaris, an invasive alien species native to North America that has been colonizing the Reserve (Fig. 4). Fortunately, eradication campaigns, led by Saint Joseph University, in coordination with local authorities and the Reserve managers, have managed to halt the spread of the invasive species.

Fig. 3: Beirut sand dunes distribution before and after construction of Beirut airport and highway.

Astragalus berytheus is categorized as Endangered globally and Critically Endangered nationally in Lebanon. Without adequate conservation measures, A. berytheus would most likely go extinct in Lebanon. As the species bears Beirut’s name, this would be a particularly marked loss. We have therefore implemented multiple conservation measures to help A. berytheus thrive, employing both in situ conservation methods on the only natural population remaining, in Tyre, and ex situ methods, storing a sample of seeds in the national seed bank. In addition, we have used the innovative approach of introducing plants grown from ex situ germinated seeds into a protected area with ecological attributes similar to the species’ original habitat.

Fig. 4: Eradication of the alien invasive camphorweed Heterotecha subaxillaris, which was threatening A. berytheus, from Tyre Nature Reserve.

Under the Conserving and Valorizing the Unique Botanical Heritage of Lebanon project funded by the Critical Ecosystem Partnership Fund, seeds of A. berytheus were grown in the seed germination and conservation laboratory of the NGO Jouzour Loubnan. Although the seeds were not difficult to germinate, it was a challenge to gather healthy seeds free from chalcid infestation. In collaboration with the Directorate General of Antiquities and the Tyre archaeological site’s manager, plantlets and seeds of A. berytheus were introduced to an archaeological site in Tyre in February 2020.  Seeds were planted in an area away from tourist trails but still visible to visitors (Fig. 5). The Tyre archaeological site is a UNESCO world heritage site that is formally protected. By July 2020 the seeds had germinated and the plantlets were developing vigorously (Fig. 6). The presence of endemic plants on an archaeological site is an opportunity to raise the awareness of visitors about the importance of conservation and its impact on both natural and cultural heritage.

Fig. 5 (left): Tyre archaeological site, with the area dedicated to A. berytheus in the centre. Fig. 6 (right): Plantlet of A. berytheus in Tyre archeological site.

In light of this encouraging pilot introduction at the Tyre archeological site, additional plants will be introduced next year to several suitable areas along the Lebanese coast. In particular, we are targeting Beirut International airport for the reintroduction of A. berytheus in Beirut, as this is where the species was originally discovered.These conservation actions for an endemic plant species on an archaeological site demonstrate how ecologists and archaeologists can work together. This is very promising in Lebanon, where space for wildlife is increasingly scarce but where archeological sites are numerous and well-protected.

View of Tyre archaeological site, showing where A. berytheus is being planted.

All photos: Magda Bou Dagher Kharrat

The article New insights on the conservation status of the endangered coastal endemic plant Astragalus berytheus (Fabaceae) in Lebanon is available in Oryx—The International Journal of Conservation.

Magda Bou Dagher Kharrat is the director of the Biodiversity and Functional Genomics laboratory of the Faculty of Science at Saint Joseph University, Beirut. She is a plant geneticist focusing on the conservation of endemic species. She employs DNA metabarcoding technology to explore biological diversity. Her work has been crucial in defining conservation priorities for Lebanon and in creating new protected areas.