While the prints can indeed be quite beautiful, many were originally made purely for the benefit of scientific study. Prior to the invention of cameras, botanical prints were the best — if not the only — way to illustrate a plant's make-up.
Many prints were originally part of a larger collection that botany enthusiasts and collectors would subscribe to receive one at a time. As such, it's not too difficult to find several pieces from the same artist that can form a series.
It also doesn't hurt to check out older botanical books for sale. If the binding is in poor condition, I wouldn't feel too guilty buying one simply to cut out and frame the prints within.
In addition to being an inexpensive option, you'll have gathered a collection in no time!
As botanical prints have gained popularity, the art has been reworked in new forms. Artist John Derian uses similar images for his collection of decoupaged trays, like the ones shown here.
The designer of this dining room used a block-printed botanical pattern on the walls to echo the plants in the garden outside the nearby window.