•  
  •  
 

DOI

10.5642/aliso.19881201.10

First Page

81

Last Page

95

Abstract

Qualitative and quantitative data are reported for seven specimens representing six varieties of the four species of Drimys generally recognized. Tracheid length and diameter are correlated both with plant size and with severity of climate: wide, long tracheids, not fluctuating in diameter seasonally, occur in Drimys of moderate elevations in subtropical latitude; narrower, shorter tracheids, becoming radially narrower briefly in latewood, occur in Drimys from higher altitudes and latitudes. Vesturing (warty layer) on the inside surface of tracheids occurs in Drimys from latitudes and altitudes where appreciable freezing is to be expected, but vesturing is absent at lower elevations and latitudes. Vesturing may bond water to tracheid walls better so that water columns do not break under high tensions produced by such conditions as transpiration when soil remains frozen. Scalariform pitting on end walls of Drimys tracheids occurs during the first year (metaxylem), but is replaced by alternate circular pits later; injury to the cambium, even of a mild kind, results in reversion to sca1ariform end wall pitting. Tracheid wall thickness is not correlated with tracheid diameter. Tracheid-ray pits are 75% the diameter of tracheid-tracheid pits. Axial parenchyma is sparse and diffuse (occasionally cells in tangential or radial pairs). Rays are Heterogeneous Type I; ray cells commonly have bordered pits on tangential walls. Silica bodies are reported (first report for Winteraceae) in rays of three collections of Drimys.

Rights Information

© 1988 Sherwin Carlquist

Creative Commons License


This work is licensed under a Creative Commons Attribution 4.0 License.

Included in

Botany Commons

Share

COinS