CONTENTS. 



PAGES. 



Introductiow, . 5-8 



Geographic Distribution, 8 



General Morphology, 8-12 



Anatomy of the Stem, 12 



General Anatomy, 12-14 



Palaeontology, 14-15 



Polygonum, . 17-18 



Subgenus Bistorta, 19-20 



Subgenus Aconogonon, 20 



Subgenus Persicaria, 20-22 



Subgenus Amblygonon, 22 



Subgenus Tovara, 23 



Subgenus Avicularia, 23-24 



Subgenus Duravia, 25 



Subgenus Tiniaria, 25-26 



Subgenus Echinocaulon, 26 



Descriptions of the Species, 28-164 



Comparative Anatomy, 165-178 



