@article{oai:kanazawa-u.repo.nii.ac.jp:00047260,
 author = {Oda, Jiro and Nagamasu, Hidetoshi and 織田, 二郎 and 永益, 英敏},
 issue = {1},
 journal = {植物地理・分類研究, The journal of phytogeography and taxonomy},
 month = {Sep},
 note = {Schoenoplectiella ×trapezoidea (Koidz.) J. Jung & H.K. Choi has been treated as a hybrid between S. hotarui (Ohwi) J. Jung & H.K. Choi and S. triangulata (Roxb.) J. Jung & H.K. Choi or S. juncoides (Roxb.) Lye and S. triangulata. However, we found two morphological types of S. ×trapezoidea in a population of Makinocho, Shiga Pref., Japan. One has slender trigonal to pentagonal culms, shorter spikelets, and high seed fertility (A-type), and the other has thicker irregularly rather sharp tetragonal to  pentagonal culms, longer spikelets often twisted at the upper part, and low seed fertility (B-type). We carried out cytological, morphological and reproductive studies of both types of S. ×trapezoidea together with its presumed parent species, S. hotarui, S. juncoides and S. triangulata, from the populations and nearby fallow field.  Chromosome number of S. hotarui, S. triangulata, and A-type with 2n = 42, B-type with 2n = 58 and S. juncoides with 2n = 74 were found. A-type is mainly growing between S. hotarui and S. triangulata in the population and showed intermediate morphology between them so, A-type is not inconsistent with a hybrid between S. hotarui and S. triangulate. A-type also showed lower pollen stainability and seed fertility than parental species, which might support the hybrid origin of A-type. Meanwhile, B-type (2n = 58) well showed intermediate chromosome number and morphology between S. trapezoidea (2n = 42) and S. juncoides (2n = 74). Moreover, as B type showed many monovalents and heteromorphic trivalents in meiosis configurations, low pollen stainability and seed fertility, it is highly possible that B-type is a hybrid between S. juncoides and S. triangulata. The examination of the type specimens showed that the name S. trapezoidea should be retained for ‘S. trapezoidea (A type)’, a hybrid ‘S. hotarui × S. triangulata’ although we could not clearly show that this plant is really a hybrid in the present study. For ‘S. trapezoidea (B type)’, we proposed a name Schoenoplectiella ×yashiroi J. Oda & Nagam., hybr. nov. for a hybrid S. juncoides × S. triangulata.},
 pages = {31--44},
 title = {シカクホタルイの分類学的研究},
 volume = {63},
 year = {2015}
}