Cactus, Canna, and Grasses
Here are some flower beds close beside the conservatory building, showing the usual wide range of species. A systematic botanist would place the plants very differently; but Mr. Burbank purposely separates plants of closely related species, to avoid the danger of accidental cross-pollenation.
This image is from: Luther Burbank: his methods and discoveries and their practical application. Volume 12 Chapter 2