Abstract
A new hybrid, Schoenoplectiella ×naritaensis Yashiro nothovar. bizenensis O. Yano & Torimaru (Cyperaceae), is described. This hybrid may be derived from crosses between S. mucronata var. mucronate and S. hotarui, which grow sympatrically in a wetland in Bizen-shi, Okayama Prefecture, western Japan. Morphological, cytological, and DNA sequence data were used to clarify the origin of the hybrid. Morphologically, the hybrid is intermediate between S. mucronata var. mucronata and S. hotarui, or overlaps with one or the other species. Moreover, the hybrid is distinguishable from the morphologically similar hybrids “S. ×naritaensis” (S. hotarui × S. mucronata var. tatarana), S. ×trapezoidea, and S. ×yashiroi, by characteristics of the rhizomes, culms, anthers and achenes. Chromosome numbers were observed to be 2n = 38 for S. mucronata var. mucronata, 2n = 44 for S. hotarui, and 2n = 41 for S. ×naritaensis nothovar. bizenensis. The nrITS data showed the sequences from S. ×naritaensis nothovar. Bizenensis to include sequences from both S. mucronata var. mucronata and S. hotarui. The morphological, cytological, and DNA sequence data suggest that the hybrid arose by natural crossing between S. mucronate var. mucronata and S. hotarui.
