An account of the vegetation of the island based upon his collection was published by Sereno Watson in Volume 11 of the Proceedings of the American Academy, 1876; and a description of the birds by Robert Ridgway in a bulletin of the Hayden Survey.
Immediately after his return from Guadalupe Island Dr. Palmer began to collect botanical and ethnological material in southern California for the approaching Centennial Exposition at Philadelphia. It was at this time that he crossed the boundary line into Mexican territory and made his famous collection of plants in the great canyon of the Cantillas Mountains, in the northern part of Lower California, a locality never before visited by a botanist, which yielded a number of new and interesting species. The collections were of special importance, and added much to the knowledge of the botany of the region. Many of Dr. Palmer's notes were embodied by Gray and Watson in their "Botany of California," which was then in preparation. He also visited the Diegueño Indians of southern California and obtained valuable material illustrating their arts and habits of life; their weapons, baskets, pottery, foods and medicines.
On one of his collecting expeditions near the Lower California boundary line he came upon a party of almost naked Cocopa Indians gathering their annual supply of pine nuts, the fruit of Pinus quadrifolia.
"It was an interesting sight," said he, "to see these children of nature with their dirty laughing faces, parching and eating the pine nuts. They had already filled many bags and were eating them by the handful. Indeed we found the piñones to be rich and well-flavored, and we were not satisfied with few. "We realized that these happy free people were in their natural habitat here beneath the pines. At last we had the privilege of seeing primitive Americans gathering their uncultivated crop from primæval groves."
Another plant collected by Dr. Palmer proved to be the type of a new genus, which Professor Gray named Palmerella in his honor, stating that he did so in acknowledgment of Dr. Palmer's "indefatigable and fruitful explorations of the botany of the southwestern frontiers of the United States, from Arizona to the islands off Lower California, in which region he has accomplished more than all his predecessors."
Dr. Palmer sent a fine collection of woods to Dr. Vasey, who was preparing an exhibit of forest trees of America for the Centennial Exposition.
- Ridgway, Robert, "Ornithology of Guadalupe Island, Based on the Notes and Collections made by Dr. Edward Palmer," Bull. Hayden Survey, No. 2, p. 183, 1876. See also by the same author, "The Birds of Guadalupe Island, Discussed with Reference to the Present Genesis of Species," Bull. Nuttall Ornitholog. Club, Vol. 2, p. 58, 1877.