Chara squamosa (Characeae, Charophyceae) in Serbia - insights from the taxonomic revision of the BEOU charophyte collection and recent field records

Chara gymnophylla is one of the first charophyte species reported for Serbia during the late 19th and the early 20th centuries, and at that time it was the second in terms of the frequency of its occurrence in the country. General taxonomic misinterpretations in the past resulted in the concealment of another species, C. squamosa, within the findings attributed to C. gymnophylla. In Serbia, Chara gymnophylla was treated as C. vulgaris var. gymnophylla, and as such was not listed as a species inhabiting the country. Recent improvements in the taxonomic concept for C. squamosa prompted a revision of the rich material of C. gymnophylla, C. vulgaris var. gymnophylla, C. vulgaris var. nitelloides, and C. rohlenae, deposited in the BEOU collection. The revision process was conducted concurrently with fieldwork and the collection of new material. Our study confirmed the presence of C. squamosa in Serbia for the first time. Based on numerous revised samples from the BEOU collection, as well as recently collected specimens, the species’ continuous presence in Serbia since 1976 was confirmed. Chara squamosa and C. gymnophylla were thus added to the list of Characeae species inhabiting Serbia, and categorised as Critically Endangered according to the criteria outlined by IUCN. An overview of the biogeography, ecology and taxonomy of C. squamosa in Serbia is provided, particularly in relation to C. gymnophylla. The BEOU charophyte collection proved to represent a valuable and relevant resource for critical taxonomic revisions. The results presented in this study strongly encourage further studies on C. squamosa and C. gymnophylla distribution in the Balkan region and wider area in order to gain a deeper understanding of the species’ ecology and the further improvement of their taxonomic concepts.
Chara gymnophylla jedna je od prvih vrsta pršljenčica zabeleženih u Srbiji krajem 19. i početkom 20. veka, i tada je na našim prostorima bila druga po učestalosti javljanja. Pogrešna taksonomska tumačenja u prošlosti dovela su do toga da je još jedna vrsta, C. squamosa, bila skrivena među nalazima vrste C. gymnophylla. Chara gymnophylla je pak kasnije u Srbiji taksonomski tretirana kao varijetet - C. vulgaris var. gymnophylla, i kao takva nije bila na listama vrsta koje naseljavaju teritoriju Srbije. U skorije vreme sugerisan je novi taksonomski koncept za vrstu C. squamosa, što je podstaklo reviziju bogatog materijala C. gymnophylla, C. vulgaris var. gymnophylla, C. vulgaris var. nitelloides i C. rohlenae, deponovanih u kolekciji BEOU. Proces revizije se odvijao paralelno sa terenskim istraživanjima i prikupljanjem novog materijala. Naša istraživanja su pokazala po prvi put prisustvo vrste C. squamosa u Srbiji. Zasnovano na brojnim revidiranim uzorcima iz kolekcije BEOU, kao i uzorcima prikupljenim u novije vreme, povrđeno je kontinuirano prisustvo ove vrste u Srbiji počev od 1976. godine. Chara squamosa i C. gymnophylla su dodate na listu vrsta pršljenčica koje naseljavaju teritoriju Srbije i klasifikovane su kao kritično ugrožene (CR) prema kriterijumima IUCN. U ovom radu dat je biogeografski, ekološki i taksonomski pregled vrste C. squamosa u Srbiji, u odnosu na vrstu C. gymnophylla. Kolekcija pršljenčica BEOU se pokazala kao dragoceni i relevantni resurs za kritičke taksonomske revizije. Rezultati prezentovani u ovoj studiji snažno podstiču dalja istraživanja distribucije vrsta C. squamosa i C. gymnophylla na Balkanu i na širem području, kao korak ka daljem rasvetljavanju njihove ekologije i utemeljenju taksonomskih koncepata.