He was an expert on the flora of Jackson County, Missouri, and his lifelong research into the plant life of that area made it into one of the best known botanical regions in the United States.
[1] Bush developed a love of the natural world as a young man by exploring the frontier country of post-Civil War western Missouri.
[1] Bush's interest in the plant life of Jackson County stemmed in part from receiving a copy of Alphonso Wood's Class-Book of Botany as a young man.
Later, Bush began a collaboration with Kenneth Kent Mackenzie, and the two of them produced several papers on plants in Missouri and used their collecting experience from expeditions in the state to publish the Manual of the Flora of Jackson County in 1902.
[4] Bush cultivated relationships with many important botanists, and he spent time collecting with Ernest Jesse Palmer and Arnold Arboretum director Charles Sprague Sargent.
[3] His business was aided by the large number of Mexican and Italian laborers brought into the area by Santa Fe Railway to do maintenance work on the line that ran near Courtney.
Among them were Quercus arkansana, Hamamelis vernalis, Crataegus missouriensis, Callirhoe bushii, Fraxinus profunda, and Echinacea paradoxa (Bush's purple coneflower).