Arthur Cronquist was born on March 19, 1919, in San Jose, California, but he grew up outside of Portland, Oregon, as well as in Pocatello, Idaho.

His parents divorced when he was young and he and his older sister were brought up by his mother, who worked for the Union Pacific Railroad in Pocatello.

Due to a childhood accident, Cronquist's right arm was partially disabled, making him unfit for military service in World War II.

Before returning to the New York Botanical Garden where he would spend the rest of his career, he worked as a botanist in Brussels with the U.S. Foreign Aid Program from 1951 to 1952.

He died of heart failure on March 22, 1992, while studying specimens of Mentzelia at the herbarium at Brigham Young University.

While working on the project in the 1960s, Cronquist came to be close friends with Armen Takhtajan and both men put all of their information at one another's disposal.

To this end Cronquist decided to learn Russian in order to have access to the scientific literature that the Soviet Union had accumulated, which was largely unknown to the rest of the world.