New methods for determination of C-3, C-4 and CAM-type plants

Numerous methods have been elaborated for the determination of photosynthet ic ability in various plants, but they are all complicated and require soph isticated equipment. In the present paper a modified version of the light m icroscope technique reported by Crookstonn and Moss (1974) was used to meas ure the number of mesophyllic cell rows and me distance between the vascula r bundles in leaf samples of three plants from each of 379 different plant species. In this way it was possible to distinguish plants of the C-3 and C -4 types extremely easily and reliably. Using the new deuterium method it a lso proved possible to identify plants of the CAM type and distinguish them from C-3 and C-4 plants in two different plant families.