• Korean Journal of Plant Taxonomy
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• v.41 no.4
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• pp.315-323
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• 2011

To elucidate the taxonomic status of the genus Megaleranthis Ohwi, a monotype in Korea, its distribution and morphological characteristics were studied and a cluster analysis was performed. The cluster analysis showed that Megaleranthis was separately clustered from Trollius and Calathodes. Megaleranthis is morphologically different from Calathodes Hook.f. et Thomson in having petals, and from Trollius L. in having an involucre instead of a caulescent leaf under the flower and follicles with simple veins. The three genera above are distributed independently within Asia, although they can be found together at the boundaries where their distributions overlap: Trollius and Calathodes occur together between the Sichuan and Yunnan provinces in China, and Megaleranthis and Trollius can both be found on the northern edge of the Korean Peninsula. From both a morphological and a distributional viewpoint, Megaleranthis should be recognized as an independent genus different from both Trollius and Calathodes.

• Korean Journal of Plant Taxonomy
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• v.38 no.1
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• pp.1-16
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• 2008

Anatomical features of seed coat were examined on Trollius, Calathodes, and Caltha of Ranunculaceae to evaluate the taxonomic circumscription of Megaleranthis saniculifolia, which is monotypic and endemic in Korea. Megaleranthis saniculifolia showed the exotestal type of seed coat exhibiting a well-developed palisade structure in exotesta and its external surface of exotesta cells was concave. On the other hand, the shape of exotesta cells in Caltha was cuboidal and the outer surface was smooth. The exotesta of Calathodes seeds was formed of the palisade structure like M. saniculifolia, but the outer surface of exotesta cells was smooth. The palisade structure was much better developed in the exotesta of Calathodes as well as Megaleranthis seeds than in the exotesta of Trollius seeds. The outer surface of exotesta cells in Trollius was either convex or concave according to the species examined. Since the genera of the subtribe Calthinae of the family display differences in seed sculpturing and the anaotmy of seed coat, these characteristics are useful to access taxonomic relationships among them. The morphological and anatomical features of seed coat suggest that Megaleranthis be possibly allied with Trollius rather than Caltha or Calathodes. Concave surface of seed coat cells and well-developed palisade structure of exotesta are shared by M. saniculifolia and some species of Trollius in common.