RADIAL STRUCTURES IN STOMATA OF OURATEA SPECTABILIS (MART) ENGL

In living, untreated Stomata of Ouratea spectabilis a radial structure originating in the stomatal opening was observed, which may be demonstrated by means of various stains. It is not identical with a cuticular striation. These structures are shown to be ectodesms visible without use of special methods because of their peculiar properties (size etc.). The method of Bancher, Hölzl and Klima allows to demonstrate that these ectodesms may secret fluid droplets. Salts (thallium and manganese) taken up with the transpiration stream are concentrated in the cell lumen and in the ectodesms. Obviously, the ectodesms are the pathways of peristomatal transpiration. © 1968 Springer-Verlag.