American farmer and botanist responsible for the botanical exploration of much of eastern Oregon. Born in Adams County, Illinois, he grew up and began his schooling in that state before his family joined many others on the great westward migration along the "Oregon Train" in 1853. Settling near Kingston in Linn County he continued his schooling there and at the age of 20 attended the Lacreole Academy in Dallas. For a few years Cusick taught school children before entering the Willamette University to study mathematics, physics and geology in 1864. Only completing one year, he joined the Union Army towards the end of the Civil War and was stationed in Fort Lapwai, Idaho, and other locations in Oregon.
With an interest in plant life since childhood, Cusick had received no formal botanical training, but while passing the time on his military duty he began to study Asa Gray's "First Lessons in Botany", a text which enabled him to identify the plants he saw around him. After his discharge in 1866 he settled near Salem, Oregon, and resumed his teaching activities while also developing his own small farm. In 1872 Cusick joined his brother, Frank Cusick, in obtaining a ranch in the east of that state and began to turn his attention more seriously to the study of botany. From about 1880 he embarked upon a correspondence with Gray and Dr. S. Watson who taught him a great deal. From 1887, when the brothers moved to North Powder and purchased adjoining farms, William Cusick's largely pastoral holding allowed him much more time to pursue botanical excursions. Almost every year he spent the season collecting, visiting various regions of Oregon and selling his duplicates. Cusick identified many of his specimens himself, although those he struggled with were sent to Watson, and Charles V. Piper (chief agrostologist at the US Department of Agriculture) and over the years he discovered several new taxa. He did not, however, publish extensively and the only two papers he is known to have produced are "Forest fires in Oregon" (1883) and "Ribes aureum" (1890).
In the late 1880s Cusick explored Malheur and Harley Counties and the Wallowa Mountains as well as the Santa Rosa Mountains of Nevada and Seven Devil Mountains in Idaho. In 1892, he married and adopted two sons from his wife's previous marriage. In 1894 she passed away and Cusick was left to look after the boys, a task which prevented him from pursuing his botanical activities for many years. Able to resume collecting in 1899, he worked his way through the eastern counties and in 1901 journeyed down through the central part of Oregon to the south-west. This was the last of his commercial trips, but he continued to work in the Wallowa and Blue Mountains until 1913 when he sold his entire herbarium to the University of Oregon. Missing his collection of specimens, however, Cusick immediately set to work gathering a new herbarium which by 1921 numbered 3,600. A stroke had, at this time, significantly reduced his eyesight to the point where he was no longer able to work on his specimens and so he once again sold his collection, this time to the State College of Washington. He died at the home of his brother the following year. The Ubelliferae genus Cusickia M.E.Jones was named in his honour, and many plants have been adorned with the specific epithet cusickii.
Sources:
H. St. John, 1923, "William Conklin Cusick", Rhodora, 25(295): 101-105
F.A. Stafleu and R.S. Cowan, 1976-1998, Taxonomic Literature, 2nd edition (TL-2), 4: 519-520
E.P. Thatcher, 1976, "Oregon Plant Collectors 1870-1940", Taxon, 25(1): 211-224.