Wondering about the botanical names of native plants, I noticed many of them had the species name "lemmonii." I decided to find out why they were so named. Many plant species names describe something about the plant such as Linium perenne (Blue Flax) where the "perenne" indicates that it is a perennial, or Lonicera japonica (Japanese Honeysuckle) where the "japonica" indicates that it is from Japan. I at first thought "lemmonii" might mean that a plant was lemon scented or had lemon-yellow colored flowers. It proved to be much more interesting than that.
The plants are named after John Gill Lemmon (1832-1908). He was always referred to as "J. G." Mr. Lemmon came out of Andersonville Prison in Georgia after the Civil War, emaciated and feeble, but a survivor. He said that after a year of rest and a liberal diet he weighed all of 90 pounds. He recuperated at his family home in California and began botanizing there. His name is often mentioned in California botany literature. His health was never fully returned to him and he was a kind of semi-invalid the rest of his life. When he was 48 years old he married Sara Allen Plummer (1836-1923). Many said the marriage was a convenience to him so that he would have someone to take care of him and help him with his work. The two spent their honeymoon botanizing in the Catalina Mountains near Tucson. They wanted to climb higher but because of the terrain and the fact that General Carr, the founder of Ft. Lowell near Tucson, stated that the Catalina's were an Apache stronghold they weren't able to do so. Later they went North of Tucson to Oracle and were able to climb to the peak of what is now Mount Lemmon from that approach. They ascended the peak with Emerson Oliver Stratton, who named the peak Mt. Lemmon. It is possible that Mr. Stratton named the mountain after Sara, not J. G. Lemmon, since she was the first white woman to set foot on it.
The Lemmon's collected extensively in Southern Arizona from 1880 to 1882, discovering many plants new to science. In 1882 they made a trip from Tucson to botanize in the Huachuca Mountains near Sierra Vista. They planned to stay at a ranch belonging to friends on the way, but when they got to it they found their friends had been scalped and the ranch burned to the ground. They camped there overnight and continued on and were guests of the Commanding Officer of Fort Huachuca while botanizing the area. While they were in the Huachuca Mountains they met a small band of Apaches in war paint. The Apaches searched them, opened the plant presses they carried with them to use as they collected plant specimens, and finally the Chief tapped his forehead indicating that these were "crazy people." Apparently the Apaches were superstitious of harming a "crazy person" and they were spared. A reporter eventually wrote about their 1882 adventures in an article in Ladies Home Journal.
The plant specimens that were collected by the Lemmon's always carried a label reading, "J. G. Lemmon & Wife" (much as a person would name a business "Jones & Sons"). There is a long list of plants discovered in the Huachuca Mountains by J. G. & Wife, including Tagetes lemmonii, Ipomoea lemmonii, Eriochloa lemmonii, Tripsacum lemmonii, Salvia lemmonii, Acacia lemmonii, and Mimosa lemmonii. Several plants such as Plummera floribunda and Stevia plummerae, found in Arizona by the Lemmon's were named after Sara's maiden name. It is estimated that these two discovered and named about 3% of all the native plants found in the state.
More information and a bibliography is available in the Cooperative Extension Office in Desert Plants, Vol. 1 Number 1, August 1979. (Published by the University of Arizona for the Boyce Thompson Southwestern Arboretum.)