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A Comparison of the Secondary Xylem Elements of Certain Species of the Amentiferae and Ranales

Alice E. Petersen
Bulletin of the Torrey Botanical Club
Vol. 80, No. 5 (Sep. - Oct., 1953), pp. 365-384
Published by: Torrey Botanical Society
DOI: 10.2307/2482083
Stable URL: http://www.jstor.org/stable/2482083
Page Count: 20
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A Comparison of the Secondary Xylem Elements of Certain Species of the Amentiferae and Ranales
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Abstract

1. The old question of the "primitive-or-specialized" status of the "Amentiferae" has been recently revived by the Swedish botanist, Hjelmqvist, who, in a long paper based solely on floral morphology (Hjelmqvist 1948), concludes that they are among the most primitive Angiosperms. 2. Attacking the problem from the point of view of wood anatomy, the writer selected at random 16 species of the recognized primitive order, Ranales, and 22 species of the long-debated group, Amentiferae, and examined their secondary xylem elements. 3. In a percentage comparison based largely on Tippo's criteria of structural evolution arrived at independently of any previously held idea that the Ranales or Amentiferae are primitive (Tippo 1938, 1946), the writer found the latter group to be decidedly more specialized than the former in all but three of 25 lines of specialization. Hence, from the point of view of the wood anatomy of the Amentiferae examined, there is very little to indicate that they are a primitive group. 4. The fibers of Clematis examined by the writer have distinctly bordered rather than simple pits as recorded by Metcalfe and Chalk (1950). 5. The perforation plates of Magnolia grandiflora have very narrow, complete borders, rather than no borders as recorded by Frost (1930a). Acknowledgments. The writer is especially indebted to Dr. Jennie L. S. Simpson of Hunter College who suggested this comparison and was very generous with her time and help; to Dr. Edmund W. Sinnott of Yale University who read the original manuscript and offered several helpful suggestions and criticisms; and to Dr. David D. Keck, Head Curator of The New York Botanical Garden, who went to great lengths to make specimens available at a time when, due to reorganization, they were very difficult to obtain. Other members of the New York Botanical Garden staff who were very kind in making material available were Dr. H. W. Rickett, Bibliographer; Mr. Thomas H. Everett, Horticulturist; Mr. E. J. Alexander, Curator; Mr. Louis P. Politi, Head Gardener; his very helpful secretary, Miss Bride McSweeney; Mr. Patrick Connolly, Greenhouse Foreman; and especially the ever-patient and untiring Miss Elizabeth C. Hall, Librarian. The writer also wishes to thank Dr. Harold H. Clum, Chairman of the Department of Biological Sciences at Hunter College, for his kind assistance; and Dr. Louis H. Teichman, Chairman of the Science Department of George Washington High School in Manhattan, for his interest and many helpful suggestions.

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