This image database includes microscopic images of cross-sections of blades of grass culms and leaves together with a morphological description of approx. 1,231 species from 27 monocotyledon families from Central Europe, Central Asia and the USA.
Characteristic features can be seen in the culms and leaves, some of which allow ecological interpretations.
The stiffening elements are clearly visible in the images taken with polarized light (images with a black background), which allows a differentiated description of this anatomical feature.
Each species is described with its characteristic anatomical features. The complete list of the features used is given in the book “Microscopic features of monocotyledonous plants” (Schweingruber & Berger, 2019).
Examples of features are presented here.
The material used originates from the combined herbaria of the University of Zurich and the ETH Zurich, from the herbarium of the University of Bern, from the herbarium of the Department of Botany and Zoology of the Masaryk University, Brno, from the Far East Branch oft he Russian Academy of Sciences (FEB RAS) and from the Deaver Herbarium of the Northern Arizona University.
The samples were taken from the central area of the stalks and leaves. The cross-sections were made with a microtome or by hand with a razor blade under a stereomicroscope, then stained with saffranine and astra blue for a few minutes, dehydrated with alcohol and embedded in Canada balsam ("Preparation Techniques for Plant Stem Analysis" (Gärtner & Schweingruber, 2013). The digital images were obtained with a Canon camera EOS 650D camera mounted on an Olympus BX51 microscope with transmitted and polarized light at 100× and 400× magnification. This method distinguished particularly well lignified (red) and non-lignified (blue) structures.