Ontogenetic types of stomata

A new classification of the ontogenetic types of stomata

by Fryns-Claessens E., Van Cotthem W. (1973)

Elisabeth Fryns-Claessens, University of Ghent (Belgium)

Willem R. J. Van Cotthem, University of Ghent (Belgium)


In Bot. Rev. 39(1): 71-138



Epistomatal mucilage plugs

Fig. 1 Evidence for epistomatal mucilage plugs extending into the substomatal cavity (a-i) and effect of mucilage plugs on the leaf water status (j and k). Mucilage-containing plugs in (a- i) were verified by exposure of leaves or leaf pieces to a 0.5% alcian blue solution for 24 h. ( a ), ( b ) and ( c ) microscopical cross- sections of plugged stomata of Drimys winteri, Agathis australis (trivial name Kauri-tree; gymnosperm) and Vitis vinifera ; ( d ), ( e ) and ( f ) top views on the abaxial leaf surface of A. australis , Tristania sumatrana (angiosperm) and Nothofagus dombeyi (angiosperm); ( g ), ( h ) and ( i ) 3-D reconstructions of a stomata on the abaxial leaf surface of Ficus superba (angiosperm), Podocarpus totara (gymnosperm) and Metrosideros excelsa (angiosperm) obtained with a 3-D digital incident-light microscope; ( j ) and ( k ) plots of patch output pressure P p values against the corresponding R.H. 
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Distribution and function of epistomatal mucilage plugs

by Westhoff M., Zimmermann D., Zimmermann G., Gessner P., Wegner L. H., Bentrup F.-W., Zimmermann U. (2009)

M. Westhoff,University of Wuerzburg (Würzburg, Germany)

Dirk Zimmermann, Qiagen, Hilden, germ

G. Zimmermann, University of Wuerzburg (Würzburg, Germany)

Petra Gessner, University of Wuerzburg (Würzburg, Germany)

Lars H. Wegner, Karlsruhe Institute of Technology, Germany

Friedrich-Wilhelm Bentrup, University of Salzburg, Austria

U. Zimmerman, University of Wuerzburg (Würzburg, Germany)


In Protoplasma 235(1-4): 101-105 – DOI: 10.1007/s00709-008-0029-0 –



Investigation of 67 gymnosperm and angiosperm species belonging to 25 orders shows that epistomatal mucilage plugs are a widespread phenomenon.

Measurements of the leaf water status by using the leaf patch clamp pressure technique suggest that the mucilage plugs are involved in moisture uptake and buffering leaf cells against complete turgor pressure loss at low humidity.

Stomatal guard cells

File:Plant stoma guard cells.png

From Wikimedia Commons, the free media repository

Original file ‎(648 × 647 pixels, file size: 566 KB, MIME type: image/png)

1 December 2006

image of an ”Arabidopsis” stomate showing two guard cells exhibiting green fluorescent protein and native chloroplast (red) fluorescence. |Source=”Protein Kinases and Plant Pores.” Gross L, PLoS Biology Vol. 4/10/20