Daniel Trembly MacDougal

Dr. Daniel Trembly MacDougal (March 16, 1865 – February 22, 1958) was an American botanist and writer. He is known for his work on desert ecology and as the earliest botanist to research Chlorophyll. He was the inventor of the MacDougal dendrograph, used to record changes in the volumes of tree trunks. He was a pioneer in studying the idea of Mutation Theory for controlling evolution. He helped to establish two botanical laboratories, the Desert Laboratory in Tucson, Arizona, and the Coastal Laboratory in Carmel-by-the-Sea, California.

Early life MacDougal was born on March 16, 1865, in Liberty, Indiana. His father was Alexander MacDougal (1832–1912) and his mother was Amanda Malvina Showalter (1834–1923). He married Louise Fisher on January 24, 1893. They had only one child during their marriage.

MacDougal was seen as an expert on desert ecology. He was one of the first botanists to research Chlorophyll. In 1905 he was involved in the establishment of the Plant Desert Laboratory in Tucson, Arizona, where he continued his experiments for several years with breeding studies on the Oenothera (evening primrose). He became its first director.

MacDougal studied the vegetation at the Salton Sea, a basin flooded with water from the Colorado River. In 1914, he wrote the book The Salton Sea: A Study of the Geography, the Geology, the Floristics, and the Ecology of the Desert Basin.

Publications Elementary plant physiology (1900) Mutants and hybrids of the Oenotheras (1905) Species and Varieties: Their Origin by Mutation (1905) Mutations, variations, and relationships of the Oenotheras (1907) The water-balance of succulent plants (1910) The Salton Sea: A Study of the Geography, the Geology, the Floristics, and the Ecology of the Desert Basin (1914) Hydration and growth (1920) Growth In Trees (1921)