A Note on the Morphology of Some Species of Riccia

Abstract

of the differences in the rate of evolution within some groups of biota, since few genera are known to include only two distinct species, one of which is morphologically less variable and restricted to a small area, while the other has a wide area of distribution including diverse climates, although its morphological variations are also small. Until such studies have been performed, Bryoxiphium continues to be one of the most unusual of the best-known genera of plants.