Scalariform Perforation-Plate Fine Structure


  • R. W. Meyer
  • A. F. Muhammad


Microfibrillar webs were frequently observed to connect adjacent bars of scalariform perforation plates of secondary xylem from a variety of tree species. When present, these webs occur most often in the lateral extremities of scalariform openings, where the microfibrils are in somewhat random alignment and hence are named reticulate microfibrillar webs. The number of strands increases and they appear more interwoven in openings near ends of plates. As the number of strands increases, reticulate webs in end scalariform openings grade into typical intervessel pit membranes composed of randomly oriented microfibrils. In certain species, microfibrils may also occur at fairly regular intervals across scalariform openings and exhibit a preferred orientation perpendicular to the bars. These were named orthogonal microfibrillar webs.


Barghoorn, E. S., and R. A. Scott. 1958. Degradation of the plant cell wall and its relation to certain tracheary features of the Lepi-dodendrales. Am. J. Bot. 45(3): 222-227.nCôté, W. A., Z. Koran, and A. C. Day. 1964. Replica techniques for electron microscopy of wood and paper. TAPPI, 47: 4477-4484.nEsau, K. 1965. Plant anatomy, 2nd ed. Wiley, New York.nFrey-Wyssling, A., H. H. Bosshard, and K. Muhlethaler. 1956. Die submikroskopische Entwicklung des Hoftüpfel. Planta, 47: 115-126.nFrey-Wyssling, A., K. Muhlethaler, and H. Moor. 1956. Electronenmikroskopische Präparationsartefacte dünner Cellulosemembranen. Mikroskopie, 11: 219-224.nFry, W. L. 1954. A study of the carboniferous lycopod, Paurodendron, gen. nov.Am. J. Bot., 41(5): 415-428.nIshida, S. 1970. [Research on wood structure by scanning electron microscopy II; in Japanese]. Wood Ind., 25(12): 560-564.nKelso, W. C., R. O. Gertjejansen, and R. L. Hossfeld. 1963. The effect of air blockage upon the permeability of wood to liquids. Univ. Minn. Agr. Exp. Sta., Tech. Bull. 242, St. Paul.nO'Brien, T. P. 1970. Further observations on hydrolysis of the cell wall in the xylem. Protoplasma, 69: 1-14.nOhtani, J. 1970. [Representation summary of the 20th meeting of the Japanese Wood Research Society; in Japanese]. Hokkaido Univ., Sapporo, Japan, p. 70.nPanshin, A. J., and C. De Zeeuw. 1970. Textbook of wood technology, v. 1. McGraw-Hill, New York.nWesley, A., and B. Kuyper. 1951. Electron-microscopic observations on the xylem elements of a fossil plant. Natur., 168: 137-140.nWitham, H. T. M. 1833. The internal structure of fossil vegetables found in the carboniferous and oolitic deposits of Great Britain. Adam and Charles Black, Edinburgh, (orig. not seen; reported in Barghoorn and Scott 1958).nYata, S., T. Itoh, and T. Kishima. 1970. Formation of perforation plates and bordered pits in differentiating vessel elements. Wood Res., 50: 1-11.n






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