Lloyd was born in Manchester, England, and educated at Princeton University (A.B., 1891; A.M., 1895), in New Jersey, and in Europe at Munich and Bonn, in Germany.

He was employed at various institutions of higher learning from 1891 onward.

He served on the faculties of Williams College, Pacific University, Teachers College (Columbia University), Harvard Summer School, Alabama Polytechnic Institute (professor of botany, 1906–1912), and at McGill University, in Montreal, Quebec, Canada after 1912.

Lloyd worked as an investigator in the Desert Botanical Laboratory of the Carnegie Institution in 1906 and as cytologist of the Arizona Experiment Station in 1907.

This article about an American botanist is a stub.