The American species of Drimys

With three text-figuresThe family Winteraceae is composed of six genera, of which only one, JThe family is a very homogeneous one, the various genera having in common a distinct type of wood structure, leaf vascularization, staminal structure and vascularization, and pollen grain.Prof. I. W. Bailey and the writer (1, 10) have already expressed agreement with the prevalent opinion that the Winteraceae is entirely distinct from the Magnoliaceae, and a study of the family as a whole is in preparation.The scope of the present paper is merely a taxonomic revision of the American species, which belong entirely to the genus Drimys.A large part of my discussion is based upon the careful analyses made by Prof. Bailey, who has prepared material in substantial quantities for anatomical study.An attempt to correlate the anatomical characters with the gross morphology and the geographic distribution has been made.I am also indebted to Dr. I. M. Johnston for assistance during the preparation of the manuscript.Often cited as an illustration of a genus with a bihemispheric-Antarctic distribution, Drimys also illustrates the varying degree of differentiation which may be found in two sections of a widespread genus.The representatives in the New and the Old Worlds have a great deal in common, and attempts to break up the complex into two genera â€" Drimys in America and Tasmannia in the Old World â€" are not generally accepted, nor does this division seem merited.However, it is obvious that two good sections, or perhaps subgenera, are recognizable.The American representatives of Drimys are hermaphrodite trees or shrubs, with always perfect flowers, and the stigmatic surface of the carpels is limited to the apical or subapical region, the small stigma being usually short-stipitate.The Old World species, on the other hand, are dioecious or polygamo-dioecious (the staminate flowers usually bearing sterile carpels, the pistillate flowers being either with or without functional stamens), and the stigmatic surface is extended along the entire ventral suture of the carpel.