Selden Richard Warner, or S.R., was born in Dunnsville, Virginia on January 27, 1885. He had two brothers, Charles A. Warner and Thomas A. Warner.

In 1910, Warner graduated with honors from the College of William and Mary with a Bachelor of Science. During his time at the College of William and Mary, he was initiated into the Alpha Chapter of the Phi Beta Kappa honor society, the oldest academic society.

In 1912, he was teaching high school biology in Richmond, Virginia. Harry F. Estill, the then President of Sam Houston Normal Institute, was visiting family in Virginia when he happened to see Warner teach and hired him on the spot. Warner accepted the faculty position at SHNI and started his new career in 1912. During this time, the sciences were taught in Austin Hall, where Warner introduced new features to the program and ways of teaching. His approach to subject matter concerning biology is still a major contribution to Sam Houston State University's Department of Biological Sciences.

Along with teaching at SHNI, Warner was also the school's first Head Football Coach. Warner organized, officiated, and coached the school's first football team for two seasons, 1912-1913. The overall record of the football team when he coached was 5-4-1. Later, Warner also founded Huntsville's first golf course.

In 1915, he married Grace Miller, who taught domestic art at SHNI. They had a daughter named Mary.

In 1923, Warner was awarded his Master of Science from Cornell University and started his two-year absence from SHNI to study at the University of Chicago for his Ph.D. In 1925, he was awarded his Ph.D. and became SHNI's first faculty member to have a doctorate. His Ph.D. thesis was "Distribution of Native Plants and Weeds on Certain Soil Types in Eastern Texas." His article, "Plant Life in Texas," was published in the 1936 centennial volume of the Book of Knowledge.

During World War II from 1943-1945, Warner became the acting president of SHSTC during the periods President Harmon Lowman left for Washington D.C. for war work. In 1947, Warner retired but in 1949, on President Harmon Lowman's request came out of retirement to continue teaching. It wasn't until 1952 that Warner retired for the second and final time. Before his retirement, he had been the Head of the Biology Department for many years. At the time of his retirement, the Biology Department had increased to six full-faculty members from one as early as 1917. Throughout his retirement, Warner would often visit campus and was well known by several succeeding generations of faculty members and students.

Warner was one of the foremost authorities on plant ecology of East Texas and was given the title naturalist, a prestigious title of this era. Along with Frederic E. Clements, a plant ecologist, Warner was among the first in the United States to study plant and soil relationships as a factor affecting plant distribution patterns. He had worked with Clements when he was granted a fellowship to study at Washington University and the St. Louis Botanical Gardens. Warner had also discovered a new plant species within Walker County, Texas. The plant species was given the name Crotargus Warneri, in honor of Warner finding the plant. Crotagus Warneri is a speciman of the red haw and only one plant was found during a summer drought of the given year (unknown).

Warner developed a 15,000-specimen herbarium, which was in the Halley Building on campus, but in 1978 the herbarium was destroyed in a fire. In 1984, through efforts of a foundation, his family created a new herbarium and was named in his honor. The Warner Herbarium is in the Lee Drain Building. The Department of Biological Sciences has a scholarship in his honor, the S.R. Warner Academic Scholarship.

Selden Richard Warner died on August 10, 1976. His wife Grace died in the same year; both lived out their lives in Huntsville, Texas.

Some of Warner's publications that are of note; "Soil, Vegetation and Ecological Successions in Walker County as Related to Wildlife," "A Comparative Study of Grazed and Ungrazed Quadrants on Two Forest Types in Southeast Texas," and "Some Quail Food Plants of Southeast Texas.