The How-To’s of Botanical Illustration

As a science illustrator, people often ask how I begin one of my drawings. Never really realizing it, I notice that the process begins before I even pick up a pencil. Scientific illustration is a form of art that serves to (accurately!) communicate scientific concepts, ideas, and findings to an array of audiences. As such, I begin by observing the botanical specimens for hours even before I begin the preliminary drawings. The curator and I will make a list of what plant characteristics to include and from there the drawings commence.

  Above is a highly simplified version of what my desk would look like during the process of creating any kind of illustration. You can see that tracing paper, various sizes of ink pens, small mechanical pencil, transfer paper, and vellum paper are all involved. The process all begins on sheets of tracing paper.

  One of the important aspects to include in a past botanical plate was the flower bud. The flower bud we’ll focus on here came from a newly discovered plant species from an Academy expedition to South America. Once I have the subject in front of me, I immediately break the subject down into basic geometric shapes (as seen above). At first this flower bud seems simple, but keep reading and you realize the miniscule details that made this subject a bit difficult to illustrate. Often I will (mentally) place the object in a grid to keep track of proportions and symmetry. Then from there slowly add details (accurately!) and the drawing becomes more and more complex.

  As you can see, this flower bud quickly became much more complex. Above, you can notice the calyx knobs (look like flaps, or wings), and the small wart-like projections towards the base of the bud. The process continues on and I begin adding all the hairs that protrude from the warts and along the calyx lobes and petals. Getting more detailed, I noticed that the plant hairs broke off into even smaller hairs, and some of these hairs ended with a glandular structure. Function of the glandular structure is still unknown. Once I have finished accurately rendering the subject, I take all my preliminary illustrations to the curator for approval. Sometimes these illustrations need to be bigger, include a bit more detail, add hairs here or there, or even redraw in a different angle.

  After the preliminary illustrations are approved, I transfer the sketches from the tracing paper onto the final vellum paper, where I will render the subject in pen and ink. Once the shape is down, I illustrate the subject as if lit from a single source of light (traditionally from the top left) and use light and shadow to show the form. Above on the left, you see the final illustration of the flower bud in pen, the scale bar, and my little signature in the corner. On the right, you see the flower bud in the final botanical plate for this species.

  The illustration above is another example of the step-by-step process I use to scientifically illustrate a botanical subject for a plate describing a newly discovered species. Once the entire botanical plate is assembled, it is used to aid the taxonomic description in the final publication describing the species. Above, you see the flower of another newly described plant species I illustrated from South America (also collected on an Academy expedition).

  The image above acts as another example of the botanical specimen I will be given and the illustration of the species on the right. You can notice minute details of the plant that require a microscope. Microscopes definitely help, but one of the big aspects of botanical illustration is the reconstruction and assemblage of broken or missing pieces.   Reconstructing these broken and missing pieces (e.g. flowers, fruits, cross-sections, etc.) is necessary as all aspects of the plant are absolutely critical to fully describe the new species. It is one of the most crucial parts to scientific illustration, and is one of the main reasons this traditional art form still exists!  

Sean Vidal Edgerton, Science Illustrator
Botany Department - California Academy of Sciences
http://www.theillustration.co/