Bolboschoenus (Cyperaceae) in the Maltese Islands – an enigma of taxonomic interest. ESF1

Mifsud, S.: Bolboschoenus ( Cyperaceae ) in the Maltese Islands – an enigma of taxonomic interest. — Fl. Medit. 32: 53-71. 2022. — ISSN: 1120-4052 printed, 2240-4538 online. This work aimed for a taxonomic investigation conducted on populations of Bolboschoenus ( Cyperaceae ) growing in wetlands throughout the Maltese Islands. A detailed account of the ecology and morphometric analysis of eleven flower-bearing populations is provided and sup-plemented by images. Emphasis was made on the inflorescence and the achenes, whereas paly-ological observations were also included. No significant taxonomic difference has been found between ray-bearing and rayless plants and all examined material did not correspond to B. maritimus , the only species reported in previous floristic literature. Findings instead showed two distinct morphotypes that are undocumented. The one prevailing in mainland Malta was completely sterile (a unique finding for the genus) except for one small population, which harboured fragment pockets of fertile plants corresponding best to B. glaucus s. l. The other morphotype occurred only on the Island of Gozo and consisted of achene-producing plants that did not match any of the described Bolboschoenus species. Morphometrics indicated an intermediate position between B. glaucus and B. maritimus . Further investigations that are more diagnostic from morphometrics are advocated for reliable taxonomic conclusions of both populations, pos-sibly leading to the first records of the hybrid B. glaucus × maritimus , as indicated in this morphological study.