I have to disagree with the recent suggestion that "sclerenchyma should be
abolished". In wood anatomy, `sclerenchyma' conveys the concept of
secondary-walled and lignified cells distinct from tracheary elements.
That is, sclerenchyma lack bordered pits whereas tracheary elements (at
least those of secondary xylem) exhibit bordered pits. The distinction is
important, not only from the functional stand point of whether or not the
mature element is capable of water conduction, but also from the
developmental stand point of cellular differentiation and its regulation.
`Prosenchyma' has largely disappeared from our terminology; however, for
early botanists prosenchyma comprised all woody elements (i.e., both
sclerenchyma and tracheary elements), whereas parenchyma comprised all soft
cells, whether present in xylem or elsewhere. In my view, the use of these
two terms was, and still remains, a useful starting point in anatomical
classification.
**********************************************************************
Rod Savidge, PhD, Professor | E-mail: savidge at unb.ca
Faculty of Forestry and \|/
Environmental Management \ | / Phone: (506) 453-4919
University of New Brunswick _\/ | \/_
Fredericton, NB CANADA \|/ Fax: (506) 453-3538
E3B 6C2 |
