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Bracken fern (Pteridium aquilinum)
Anomalous stomata on polyploid bracken.
by Takahashi C. (1960)
Chihiro TAKAHASHI, Biological Laboratory, Department of General Education, Nagoya University
in Bot. Mag. Tokyo 73. 160 –
https://www.jstage.jst.go.jp/article/jplantres1887/73/862/73_862_160/_article