1991 Volume 42 Issue 2 Pages 125-137
In order to clarify its origin and status, Drosera tokaiensis (Komiya & C. Shibata) T. Nakamura & Ueda, comb, et stat, nov. (=Drosera spathulata ssp. tokaiensis), a member of the Tokai hilly land elements, is studied and compared to D. spathulata and D. rotundifolia. Our analysis shows that D. tokaiensis is intermediate between D. spathulata and D. rotundifolia in the gross morphology of seeds and stipules as well as the area covered with glandular hairs on a leaf. D. tokaiensis (2n=60=20L+40S) further has an amphidiploid condition, with a chromosome constituent derived from both D. rotundifolia (2n=20=20L) and D. spathulata (2n=40=40S). Available evidence thus suggests that D. tokaiensis is of hybrid origin between D. spathulata and D. rotundifolia. A geographical variation of D. tokaiensis is also discussed on the basis of comparison between the populations of the Kinki and Tokai Districts of Japan.
