Charles Bixler Heiser Jr. (October 5, 1920 – June 11, 2010) was a professor of botany, known as a leading expert on the sunflower genus Helianthus.

"[2] After graduating from Belleville Township High School, Illinois, where he was the senior class president, Heiser attended Washington University in St. Louis.

[5] In 1945 he began study for his Ph.D. at the University of California, Berkeley, where he worked with G. Ledyard Stebbins on the genetics of sunflowers, although Louis Mason was Heiser's official doctoral advisor.

[4] In 1953, as a Guggenheim Fellow, he went on sabbatical leave in Costa Rica to study chili peppers and learn about the local flora.

At the Instituto Interamericano de Cooperación para la Agricultura in Turrialba, Costa Rica, he met two students from Ecuador: Jorge Soria and Jaime Díaz.