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Botany

A new species of willow is discovered in Catalonia

Common in the northern regions of Europe, Asia and North America and in some mountainous areas further to the south, the willow Salix hastata is very rare to find in the Pyrenees. This is the first time its presence has been confirmed in Catalonia.

STAFF | AUGUST 20th, 2010

Example of Salix hastata

The Nature Park of the High Pyrenees is home to a willow species seen for the first time in Catalonia. It was discovered in the summer of last year by researchers conducting field work on protected and endangered flora located in the park. At that time, the tree’s species could not be identified with certainty, but, after some samples were examined, it was confirmed that the species was Salix hastata.

This willow lives in the northern regions of Europe, Asia and North America and in some mountainous areas further to the south. In the Pyrenees, its presence is extremely rare. Until now, it had only been found in two or three places at this latitude, while in Catalonia its only recorded presence was in Aran in the nineteenth century, and this was considered very doubtful.

The willow was found in the Marimanya Valley, near the Noguera Pallaresa and the boundary between the Pallars Sobirà and Aran. The discovery was made by the botanist Peter Aymerich, who works regularly following plant development in this protected area.

The willow was found in the Marimanya Valley, near the Noguera Pallaresa This year, the Nature Park of the High Pyrenees initiated a study to know the status of this plant and has counted an estimated population of 500 individuals located along the Marimanya river through a stretch of about 700 meters with high densities in some areas.

This willow has the peculiarity of being very variable in terms of its size and the shape of its leaves to the extent that individuals can easily be mistaken as belonging to different species. There are two main types, both represented in Marimanya: those with a typical bushy appearance and those appearing to be dwarf willows.

Those with a bushy form grow along the river, are about one meter in height, with many branches and relatively large leaves. In contrast, the dwarf individuals do not grow more than 10 to 50 centimeters off the ground, are hardly visible on the surface and have very small branches and leaves. These dwarf-like individuals grow on peatlands and have a look reminiscent of other dwarf-willow species found in high mountain environments.

The Catalan Department of Environment and Housing is considering the future inclusion of Salix hastata in the list of threatened flora of Catalonia (Decree 172/2008).

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