CHAPEL HILL - Pretty much all the work produced by students in the North Carolina Botanical Garden’s Botanical Illustration Certificate Program during its early years was, as you might expect, straight botanical illustration.

Meaning detailed depictions of individual plant species, drawn in pen-and-ink or graphite and sometimes colored with watercolor or colored pencil, rendered against a white background, with particular emphasis on clearly and accurately portraying identifying anatomical and taxonomic features. Botanical illustrations are often beautiful – they remain popular for framing and hanging on walls – but their primary goal is scientific accuracy.

So it may be a little startling to see a piece like Beverly Dyer’s “Backyard Bouquet” in “Botanicals and Beyond,” an exhibition of works by graduates of the Botanical Illustration Certification Program now on display at the garden. The entire surface of the painting is awash in brilliant hues that run together in almost abstract splashes of color, with the forms of leaves and flower blossoms only vaguely suggested. If there’s a precisely drawn pistil or stamen in the piece, it’s obscured beneath the giddy explosion of ochre and fuschia.

“It’s a little ironic that the piece I have in this show is so loose and expressionistic,” Dyer said. “I learned so much in the program about detail and shading and how to make things look realistic. But this particular piece isn’t all that; it’s a very loose watercolor.”

The inclusion in the exhibit of “Backyard Bouquet” and some other pieces that aren’t strictly botanical illustrations – as well as some that are – is by design, said Nancy Easterling, the Botanical Garden’s director of education.

“That’s part of the ‘Beyond’ aspect of ‘Botanicals and Beyond,’” Easterling said. “When the program began it was focused on the techniques and methods of botanical illustration. It still is, but it has also developed over time to include more artistic approaches; we refer to it now as a ‘Botanical Art and Illustration’ program.

“And the other part of ‘Beyond’ is that some of our graduates have been out of the program for a number of years and have continued to develop their own artistic expression. So it’s a very dynamic show.”

Miriam Sagasti , one of the first graduates of the certificate program, said the line between botanical illustration and botanical art can be a fine one.

“Traditionally, botanical illustration is all about making sure the plants are drawn perfectly, with fine details and no background,” she said. “A lot of artists now want to explore more with composition and background and take a more painterly approach. It implies a broader perspective. The show has a very good variety of styles.”

“Botanicals and Beyond” features works by more than a dozen graduates of the certificate program, which the Botanical Garden launched in 1991. The program includes a rigorous course of study – students learn not only artistic principles and techniques such as color theory, composition and drawing, but also scientific ones such as botany, taxonomy and plant identification.

“There’s a lot to learn, and it takes a few years,” said Miriam Sagasti, who was among the first cohort of graduates. “It’s a fabulous program, and they offer even more classes now. Almost everybody who has graduated still comes back to take classes from time to time.”

Some the program’s graduates are working as illustrators; others have careers as artists, and some make art primarily as a hobby.

“It’s very rewarding,” Dyer said. “For me it was a way to combine my love for science and art. I’ve loved learning more about native North Carolina plants and wildflowers, and I spend a lot of time outside sketching. It takes time and dedication, but it’s worth it.”