Abstract
Phenological observations of plant flowering patterns provide useful information for studying the ecological impact of global climate change over long‐term periods. However, the long‐term data sets with which meaningful comparisons can be made are rare, especially in the less‐populated Northern Great Plains region of North America. Here we present the observations of first‐flowering time of native and nonnative plant species in North Dakota and Minnesota over the course of 51 years in the last century. Orin A. Stevens recorded the first‐flowering time of 753 species in the vicinity of Fargo, North Dakota, USA, and throughout North Dakota from 1910 to 1961. These data offer baseline indications of both the timing of first flowering and the presence/absence for a wide variety of plants in a region of North America with a relatively short growing season. The complete data sets corresponding to abstracts published in the Data Papers section of the journal are published electronically in Ecological Archives at http://esapubs.org/archive . (The accession number for each Data Paper is givendirectly beneath the title.)