Each spring since 1915 a record of the date of the first appearance of flowers of our seed bearing plants has been kept. This has been handled through a contest with the students in the botany classes. Reports on the comparative dates for some of the more representative species were made in 1918 and in 1924.
Proceedings of the Iowa Academy of Science
©1934 Iowa Academy of Science, Inc.
Dodds, Ellsworth and Jaques, H. E.
"A Twenty Years Phenological Record of the Spring Flowering Plants of Henry County,"
Proceedings of the Iowa Academy of Science, 41(1), 107-108.
Available at: https://scholarworks.uni.edu/pias/vol41/iss1/17