The Science of Botanical Art

Dissection

By Dick Rauh

Originally appeared in The Botanical Artist - Volume 16, Issue 4

 

At the Pittsburgh meeting I taught a class in drawing under the microscope. I don’t know how many of you have had the opportunity to indulge in this very useful scientific tool to discover the intimate secrets of flowers, but it is one I highly recommend. If you can somehow wheedle the use of a dissecting scope, and are willing to wield a razor blade and a dissecting needle, it will open up a whole new facet of plant life.

Even if a scope is impractical, a good jeweler’s loupe can provide a wealth of information that can help to improve your drawing. What is suddenly visible, at as little as ten times magnification, can clarify relationships between parts, or illuminate textural variations that will enhance your final work.

To study the details that distinguish between species, it is helpful to begin to take apart these gorgeous blooms. A longitudinal section often reveals relationships that explain the why or how a flower has adapted. Running a single-edged razor blade vertically though the center of a blossom does this. Arthur Harry Church, a Victorian botanist and teacher (recently immortalized in Arthur Harry Church: the anatomy of flowers, D.J. Mabberley. 2000, Merrell & The Natural History Museum, London), created exquisite color renderings of these long sections. For most of us the section is a way to learn more about our flowers.

In a cross section the blade runs across the axis of the flower, usually to reveal what is happening in the ovary. If this sounds irreverent, think of what you will gain in knowledge! If you have a chance to see some of the work of Maud Purdy who was the Brooklyn Botanic Garden’s artist in residence for many years, you can see what a superbly talented scientific illustrator can do rendering such a cross section and other details she saw under the scope.

Dissection can be a little daunting. You have been looking at flowers for a long time, and because you have been drawing and painting them you have a head start on understanding what you see under the scope, but you may have some preconceived ideas that you need to overcome. I know the temptation to say “I draw what I see” makes this process a little more difficult. It is wonderful to draw what you see. It is even better to know what to see. A scientist or botanical juror is generally looking for a typical representation of a particular plant. We are dealing with nature, which is filled with variables, so you may be faced with a model that is anything but typical. Very often, because two species are alike, very subtle differences not readily visible to the naked eye are important for classification. To know what to emphasize, or if you are looking at a typical part of the flower, or when you are looking at an artifact or damage caused by bad handling, is the goal of dissection and close observation possible with magnification.

I believe the more you know about your subject, the better your final rendering will be, so think about treating your findings as preliminary research, as a way to inform yourself of the subtleties and characteristics of the species, enriching a knowledge that will make your ultimate product that much better.

To approach dissection here is what I do; see if it works for you. Check the written references about the species, and discover what the typical characters of the plant. Look at the flower without any lens. Turn it around. Try to find the point of view that best shows the general shape, and the most information about the parts. Measure the outer length and width of the flower, and perhaps the size of various parts. Draw a rectangle lightly on your paper (I tend to use tracing paper at this stage) and do a rough sketch of the entire flower (inflorescence). This is known as the habit drawing, and hopefully it includes the stalk (peduncle or pedicel) and some leaves. Write down basic information, things that look interesting, note measurements and anything that will jog your memory when you move from this preliminary study to your finished work.

Here are some questions you might ask: Is the flower solitary, or part of an inflorescence? Is the flower regular (actinomorphic) or irregular (zygomorphic)? How many series (of petals or stamens for instance)? Is the flower complete? Is the flower perfect (bisexual)? Where are the flowers attached to the stem (terminally or laterally)? How many sepals? Are they free or fused? How many petals? Are they free or fused? How many stamens? Where are they attached? What about the pistil? Is it or any parts of it visible? How many styles? Stigmas? Carpels? What is the position of the ovary? With magnification, the answers to these questions become more evident.

I have a scope handy, next to my drawing table, usually magnifying no more that 10x. Digging inside the blossom, possibly removing sepals or petals, finding out what’s happening to organs where their origins are hidden, so that filaments or styles are not aiming towards impossible starting points, are the advantages of this kind of thorough search. All of which, I think will ultimately help to make your artwork more botanically accurate, and your drawings more beautiful.

Copyrighted by the author.  Not to be downloaded, copied, reposted or republished elsewhere.

  • (C) 1906 Arthur Church