Variability of the inflorescence morphology of Carex spicata (Cyperaceae) and its implication to taxonomy

Plants growing in different kinds of habitats are expected to show high morphological plasticity. Carex spicata Huds. occurs in different plant communities and shows distinct morphological variability of the inflorescences. Field observations carried out in different plant communities permitted us to hypothesize that the morphological variability of C. spicata inflorescences may to some degree be the result of the habitat. The objective of this study was to test that hypothesis for C. spicata by collecting inflorescences and measuring their morphological features from several populations in each of six plant communities: Agropyro‐Urticetum dioiceae, Arrhenatheretum elatioris, Lolio‐Cynosuretum, Lolio‐Plantaginetum, Trifolio‐Agrimonietum, and Stellario‐Deschampsietum. The following inflorescence features were analyzed: length of the lowest spikelet, distance between two lowest spikelets, length of inflorescence, number of spikelets, and length proportion of the lowest spikelet to the distance between the two lowest spikelets. We found that all analyzed morphological characters differed significantly among the plant communities. Furthermore, we found significant differences among populations within the six plant communities. Moreover, C. spicata inflorescences often have morphological features (i.e. a less crowded inflorescence with a relatively large distance between the two lowest spikelets) similar to the closely related species C. muricata L. Thus, the limited diagnostic value of inflorescence crowding, especially in vegetative or early fruiting phases, suggests that the taxonomic importance of this character should be reconsidered.