The microscopic anatomy of the vegetative parts ofPetermannia cirrhosais described for the first time. This information lends support to the exclusion ofPetermanniafrom the Dioscorea‐ceae with which it has been tentatively associated, the vascular anatomy of the two being quite dissimilar. No satisfactory explanation of the peculiar leaf‐opposed position of the tendrils (inflorescence homologues) can be offered, except that it clearly cannot be accounted for by sympodial growth. Vascular tissues inPetermanniaare very unspeciali