American botanist, educator, and founder of the journal Phytologia. The grandson of a Lutheran missionary from East Prussia and son of Egyptologist Charles Moldenke, Harold Moldenke was born in 1909 in Watchung, New Jersey. He gained his PhD in Taxonomic Botany from Columbia University in 1934, and started his career at the New York Botanical Garden as a part-time assistant in 1929, becoming associate curator (1937-1948) under Henry A. Gleason.

During the Second World War he worked for the Soil Conservation Service, and wrote a series of papers on 'Plants Strategic to the War Effort'. In 1949 he was appointed curator and administrator of the herbarium at the New York Botanical Garden, taught a course there on systematic botany, and as a member of the Graduate Faculty (1946-1952), also lectured at Columbia University's Department of Botany.

Moldenke resigned from the Garden in 1952 to make a career in science education as director of the Trailside Museum (later the Trailside Nature and Science Center) in Mountainside, New Jersey, developing the center into a highly successful year-round facility. While there, he also taught botany at Newark State College. In 1967 he left Trailside to become a professor at William Patterson College until his retirement in 1972.

An avid collector, his field trips took him to Europe, Central and South America, the Middle East, Africa, Malaysia, Japan and every U.S. state except Alaska. He published handbooks on all the families within his field of expertise: Verbenaceae, Avicenniaceae, Stilbaceae, Dicrastylidaceae, Symphoremaceae, Nyctanthaceae, and Eriocaulaceae. In 1977 his collections numbered 31,279 and his bibliography that year amounted to 2,584 titles, including articles, lectures, pamphlets and monographs.

Once asked if the 'crown of thorns' plant sold by florists was the same as that written of in the bible, the question led him on a 12 year research study that culminated in his famous book Plants of the Bible published in 1941. His collaborator on this work was his botanist wife Alma Lance Ericson, who also worked with him on American Wild Flowers and was co-editor of Phytologia founded in 1933 and edited by her husband until 1989.

In 1955 he advised the Beth Israel Memorial Park in Woodbridge, New Jersey, on the choice of plants, shrubs and rocks imported for the cemetery's 'Bible Gardens of Israel'. Named an Honorary Life Member of the Torrey Botanical Club in 1969, he was also made Honorary Curator of the New York Botanical Garden the following year. He sold most of his herbarium, papers and books to the University of Texas in 1984. He died in Corvallis, Oregon, on January 7, 1996.