The Science of Botanical Art

Dissection 

By Dick Rauh  

Originally appeared in The Botanical artist, Number 28

 

For a change I thought I would write about a technique, instead of concentrating solely on the scientific aspects of our art. You might get a new slant on your drawing if you take a bit of time to really look closely at your model. Horror of horrors, I am making a case for tearing apart a beautiful flower - destroying it in the name of knowledge. I don't doubt that the final result, with those flowers that you left whole, will be a good deal better for the blasphemy. 

Of course if you are working with a $50 orchid or a one-of-a-kind never-to-be-replicated hybrid, even I would proceed in the old ‘superficial’ way, drawing what you see on the outside. 

Dissection can be a little daunting. You have been looking at flowers for a long time, and because you draw and paint them, you are that far ahead of botanists who don't have your eye. It is important to draw what you see, but it is equally important to know what to see, to provide yourself with a little foreknowledge about the structure of your model in areas that may be hidden by the angle of your view. The foreknowledge is there for the taking in a number of books, Zomlefer's Flowering Plant Families or Glimn-Lacey and Kaufman's Botany Illustrated to name just a couple. 

You do need some magnification, although it is remarkable how much you can see with the naked eye. Ideally, a dissecting scope is a formidable aid. What you are looking for is a binocular scope that magnifies 10x and 30x. The more expensive models come with a built in light source and that's fine, but rarely do we need to use the underneath light, and any small auxiliary light that you can aim at the stage, including setting up the scope on a sunny windowsill, will do just fine. Other models come with an adjustable magnification range (usually from 7 to 30 times) and this can sometimes prove a blessing, but it is by no means an absolute necessity. 

(Very often there are second-hand scopes available, check out the Yellow Pages and the Internet. I have recommended John Simon, a New Jersey microscope technician and have gotten good reviews. His phone number is 201.445.3001.) 

If a scope is not an investment you care to make, there are any number of fine hand lenses or hand-held magnifying glasses available, some with adjustable stands allowing you to use both hands to draw, a decided plus. The typical jewelers' loupe is a dependable 10x magnification. Local nature centers usually carry a line of magnifiers; just take your pick. A see-through 6-inch/centimeter scale is invaluable. The only other tools are a forceps (a fancy scientific way of saying tweezers!) or a couple of dissecting needles to manipulate the subject, and single- edged razor blades to make the needed sections. Don't be chintzy with blades - a sharp new blade makes a clean true cut with a minimum of squashing or distortion. 

Create a special book, just for the purpose of documenting your finds. Start a new page for each species, and indicate the name (Latin Binomial), common name and family, if you know it. Put these in the upper left of your page, just to keep it consistent. Draw the habit and whatever details interest you, or those that help clarify the distinctive features of the subject. Don't hesitate to document the drawing with whatever comments come to mind, and you will end up with a reference work that you will return to time and again. Since I know my audience is artists I'm not even mentioning drawing tools - use your favorite. 

Here is a possible agenda for discovering some of the incredible architecture and cunning artifice that flowers use to attract pollinators and effect the way they look. These are adaptations that have allowed the vast range of speciation that keeps us constantly intrigued and interested; indeed that keep us painting flowers. 

First, look at the flower without any lens, turn it around to find the angle(s) that best shows the general shape and the most information about the parts. Measure the length and width, and perhaps the size of various parts. Draw a rectangle lightly on your paper and do a rough sketch of the entire flower (inflorescence). This is known as a habit drawing, especially if you have been able to include the stem (peduncle or pedicel) and perhaps some leaves. Put down basic characteristics, things that look interesting, things that will jog your memory. The information you absorb during this process will show in the way you approach your final work. You will find that it has you refer to the notes or not. 

Here are some of the things you might be looking for: Is the flower solitary or part of an inflorescence? If it's part of an inflorescence how are the individual flowers attached? If there is a pedicel, is it subtended by a bract? Where are the flowers attached; terminally (at the top or apex of the branch) or axillary/laterally, along the sides of the stem? Is the flower regular (actinomorphic) or irregular (zygomorphic)? How many series (rows of stamens, petals, sepals)? Is the flower complete? Is the flower perfect (Having both male/female parts)? If imperfect, how are the staminate and pistillate flowers arranged? 

What about the number of parts? How many sepals? Are they free or fused? Same for the petals. Is the shape of an individual petal distinctive? Which petal is in front of the other? How many stamens? Where are they attached? Are they adnate to the corolla tube, or do they arise from the receptacle? What about the pistil? How many styles? Stigmas? Carpels? What is the position of the ovary? Superior, so that it sits on the other three series, or hidden in the receptacle, or hypanthium? 

Some of the answers to these questions may need dissections, or removal of some parts of the perianth to get a clear view of the reproductive organs. Sometimes you need to remove the stamens to see the pistil. A clear longitudinal section of the flower gives you vital information about the attachments of the various series and perhaps the reason why the ovary is shaped the way it is. If you really get into it, try a cross-section of the ovary, and see if you can figure out how the ovules are attached because this affects the shape of the ovary and sometimes the number of lobes or arms on the stigma. You can include detail drawings or paintings of the floral organs and make your piece something more meaningful and scientific than just a floral portrait. 

This may seem like an awful dose to go through each time you approach a new blossom and it’s only a bare start but after a while this list will become second nature. To begin with just concentrate on really studying the flower, and take it from there. If you are creating a scientific illustration, your client the scientist, is generally looking for a typical representation of the plant. Get a written description, or at the very least an oral one that stresses the important characteristics that define the species. Very subtle differences are extremely important for classification; things that you may need a hand lens or dissecting scope to see. Knowing what to emphasize, knowing when you are looking at a typical flower part, knowing an artifact or damage is part of the goal of dissection.