Flora Raetica: Halfway to the Flora of the Century for Graubünden

Well over a hun­dred vol­un­teers have been doc­u­ment­ing the flo­ra of Graubün­den since 2021—with 350,000 sight­ings report­ed so far and the first inter­est­ing results emerg­ing.

As part of the “Flo­ra Raet­i­ca” project, some 130 botany enthu­si­asts have so far been cat­a­loging the ferns and flow­er­ing plants of Graubün­den. By 2032, this data is expect­ed to result in a new “Flo­ra of Graubünden”—one hun­dred years after the sem­i­nal work of the same name by Josias Braun-Blan­quet and Eduard Rübel.

Already 350,000 plant observations

Since 2021, vol­un­teers have record­ed 350,000 plant obser­va­tions and doc­u­ment­ed 2,700 species. In 2025 alone, 113,000 new sight­ings were added.

“Thanks to the many new obser­va­tions, we are get­ting an accu­rate pic­ture of where spe­cif­ic plants grow in Graubün­den and how com­mon they are,” says Chris­t­ian Rix­en, co-direc­tor of Flo­ra Raet­i­ca and a researcher at the WSL Insti­tute for Snow and Avalanche Research (SLF).

Fewer field weeds, more neophytes

Even at the halfway point of the project, the grow­ing vol­ume of data is already allow­ing for ini­tial sci­en­tif­ic analy­ses. A master’s the­sis at the SLF shows that 6.5 per­cent of the species that were present in the 1930s have not been con­firmed since then. Half of these 144 species are con­sid­ered endan­gered accord­ing to Switzerland’s Red List.

Species that depend on exten­sive, small-scale agri­cul­tur­al land­scapes are par­tic­u­lar­ly affect­ed, such as low­land field plants like the sum­mer blood-drop. At the same time, new plants are spread­ing: 13 per­cent of the species record­ed today were not part of Graubünden’s flo­ra a hun­dred years ago. These include the sil­ver poplar and the Euro­pean horn­beam, as well as many neo­phytes, such as the South African rag­wort.

Surprising Rediscoveries

“Even though the data is still pre­lim­i­nary, it already clear­ly shows how much the plant life has changed over the past hun­dred years,” says Chris­t­ian Rix­en. “At the same time, we keep dis­cov­er­ing unex­pect­ed species in places where no one has looked for a long time.” For exam­ple, a mem­ber of the Flo­ra Raet­i­ca team was able to con­firm the pres­ence of the extreme­ly rare snow-white cinque­foil above Davos for the first time since 1916.

Fur­ther analy­ses are intend­ed to show how cli­mate change and changes in land use affect biodiversity—and to pro­vide impor­tant insights for the con­ser­va­tion of endan­gered species and habi­tats.

Research as a Collaborative Effort

Flo­ra Raet­i­ca is a cit­i­zen sci­ence project. The data comes not only from experts, but pri­mar­i­ly from peo­ple who devote their free time to the plant world—from a finan­cial expert in the can­ton of Zurich to a social work­er in Chur. They report their obser­va­tions via an app or par­tic­i­pate in group map­ping events. “With­out the tremen­dous work of the vol­un­teers, this project would be impos­si­ble,” says Chris­t­ian Rix­en. “It com­bines research with a gen­uine joy of dis­cov­ery.”

A Look at the Second Half of the Project

To date, regions along the main val­leys and trans­porta­tion routes have been par­tic­u­lar­ly well stud­ied. In con­trast, sig­nif­i­cant gaps remain in more remote areas such as parts of the Sur­sel­va, the Safien­tal, the Schams, the Bergell, and the Puschlav.

The plant sur­veys will con­tin­ue through 2028. After­ward, the project lead­ers will con­duct a sci­en­tif­ic analy­sis of all the data. Final­ly, a rich­ly illus­trat­ed book is sched­uled to be pub­lished in 2032—as a botan­i­cal record of our times for future gen­er­a­tions.

Contact

Co-Project Leader, Flo­ra Raet­i­ca

Chris­t­ian Rix­en Thomas Wohlge­muth
rixen(at)slf.ch thomas.wohlgemuth(at)wsl.ch
+41 81 417 02 14 +41 44 739 23 17

Flo­ra Raet­i­ca Coor­di­na­tor

Ingrid Jansen
ingrid.jansen(at)wsl.ch
+41 78 625 27 36

Flora Raetica at a Glance:

  • Flo­ra Raet­i­ca is a cit­i­zen sci­ence project. With the help of vol­un­teers, it sys­tem­at­i­cal­ly doc­u­ments the flo­ra of Graubün­den.
  • The project shows how the flo­ra of Graubün­den has changed since the last com­pre­hen­sive sur­vey by Braun-Blan­quet and Rübel 100 years ago.
  • Since 2021, 350,000 new plant obser­va­tions have been record­ed. This data serves as an impor­tant foun­da­tion for the con­ser­va­tion of bio­di­ver­si­ty.
  • Every­one is invit­ed to par­tic­i­pate in this once-in-a-cen­tu­ry project—from begin­ners to pro­fes­sion­als. Every obser­va­tion counts.
  • Con­tact and fur­ther infor­ma­tion: florae.ch

Press Photos

Even on the highest mountain peaks, unique species can be found; here, the Cenis bellflower. Photo: Michael Zehnder.
Even on the high­est moun­tain peaks, unique species can be found; here, the Cenis bell­flower (Cam­pan­u­la cenisia). Pho­to: Michael Zehn­der.
Christian Rixen identifying plants. Photo: Brigitte Wenger.
Chris­t­ian Rix­en iden­ti­fy­ing plants. Pho­to: Brigitte Wenger.
Exploring the flora on the Parpaner Rothorn. Photo: Anna-Barbara Utelli.
Explor­ing the flo­ra on the Parpan­er Rothorn. Pho­to: Anna-Bar­bara Utel­li.
Summer Pheasant's Eye (Adonis aestivalis). Photo: Andreas Gygax.
Sum­mer Pheas­an­t’s Eye (Ado­nis aes­ti­valis). Pho­to: Andreas Gygax.
South African ragwort (Senecio inaequidens). Photo: Andreas Gygax.
South African rag­wort (Senecio inae­quidens). Pho­to: Andreas Gygax.
Summer Pheasant's Eye (Adonis aestivalis). Photo: Andreas Gygax.
Sum­mer Pheas­an­t’s Eye (Ado­nis aes­ti­valis). Pho­to: Andreas Gygax.
Snow-white cinquefoil (Potentilla nivea). Photo: Andreas Gygax
Snow-white cinque­foil (Poten­til­la nivea). Pho­to: Andreas Gygax

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Copyright

Flo­ra Raet­i­ca pro­vides images free of charge for use in press cov­er­age relat­ed to this press release. The inclu­sion of this mate­r­i­al in image data­bas­es and its sale by third par­ties are not per­mit­ted.

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