Comparison of leaf epidermis in different species

by Anne Bruce

It's quite difficult to visualise that such a thin structure as a leaf is made up of several layers of cells. Imagine putting a leaf flat on a surface and cutting across and then looking end on at the cut edge. The image on the left shows what you would see under the microscope if you took a very thin slice from that cut edge. Unfortunately, without access to sharp blades or a microtome, it can be quite hard to get thin enough sections to view the cut surface in detail.

However, one layer of the leaf, the epidermis, can be studied quite easily without need or danger of sharp blades. The epidermis is the outer layer ("epi" - outside and "dermis" - skin) and is found on the upper and lower surfaces of the leaf. Nail varnish can be used to make a "cast" of this surface which can then be viewed under the microscope.

How to make your cast

• Collect a variety of leaves (trial and error will determine which sort are the "best" or "easiest" to cope with)
• Carefully paint a thin layer of nail varnish over the leaf surface - it is worth while coating upper and lower epidermis as often there is a difference between the two
• Leave to dry - again this is down to trial and error, I have found that leaving the varnish to dry for a couple of hours, or overnight gives the best results
• When the varnish is dry, use forceps to carefully peel it away from the leaf and place on a slide, preferably with a coverslip over the top
• You are now ready to view under the microscope

The images below show a variety of different leaf surfaces and it can be seen that there is not only variation between species, but also that in certain plants, upper and lower epidermis differ in stomatal distribution. (You'll find more more information on the structure and function of stomata in a previous article in Micscape ).

Comparison of leaf epidermis in different species
	Spider plant (Chlorophytum)
Bay leaf (Laurus nobilis) lower epidermis	Bay leaf (Laurus nobilis) upper epidermis	Morning Glory (Ipomoea)
Black Eyed Susan (Thunbergia alata) upper epidermis	Black Eyed Susan (Thunbergia alata) lower epidermis	Black Eyed Susan (Thunbergia alata) lower epidermis

A post script

I am grateful to Ron Neumeyer for suggesting the following tip:

Try laying a tooth pick along the leaf and include it in the varnishing process. Makes it much easier to peel off a section.

Comments on the article to the author Anne Bruce

Microscopy UK Front Page
Micscape Magazine
Article Library

© Microscopy UK or their contributors.

Please report any Web problems or offer general comments to the Micscape Editor,
via the contact on current Micscape Index.

Micscape is the on-line monthly magazine of the Microscopy UK web
site at Microscopy-UK