Carex section Racemosae (Cyperaceae) in Europe: morphological diversity, taxonomy and phylogenetic relationships

Abstract

All European taxa of Carex section Racemosae were assessed using macromorphological (mainly quantitative) and micromorphological characters (sculpture of utricles and nutlets). Morphological separation of the specimens examined was tested using discriminant function analysis (DFA). Micromorphology of utricles and nutlets was investigated using scanning electron microscopy (SEM). The results show that: (1) C. bicolor differs from other taxa in section Racemosae in macro- and micromorphological characters, justifying removal of the species from the section; (2) the morphological data support placing C. stylosa in a separate section, Stylosae; (3) morphologically, C. holostoma has a close affinity with taxa in subsection Papilliferae; (4) C. parviflora differs significantly from the remaining members of subsection Alpinae in the size and colour of the utricles and we suggest reconsidering the position of this species in subsection Alpinae; (5) morphological characters are insufficient for maintaining C. norvegica subsp. pusteriana and C. norvegica subsp. norvegica at subspecies level; (6) C. atrata, C. aterrima and C. caucasica are morphologically well-defined and valid species; (7) C. aterrima subsp. aterrima and C. aterrima subsp. medwedewii are morphologically similar and their taxonomic status requires further study, also at the molecular level.