I'm at the Denver Botanic Gardens today, doing a workshop on water-soluble colored pencils.
The Denver Botanic Gardens one of America's most extensive botanic gardens. The garden headquarters, which are currently being extensively renovated, also hosts a certificate program for botanical art and illustration.
Students who enroll in the program get a chance to study watercolor, pen-and-ink, scratchboard, colored pencil, and other techniques, as well as botanical science. For more information, visit the page on the DBG site, link., or the Botanical Illustration Blog, link.
The picture above is from Dinotopia: A Land Apart from Time. It's painted in oil on illustration board. The pencil drawing was sealed first with acrylic matte medium.