"A Thoreau Gazetteer" - Robert F. Stowell, edited by William L. Howarth
Nineteenth-century notes on flora local to Concord, Mass. have been used by Dr. Richard B. Primack and Dr. Abraham J. Miller-Rushing to determine changes in the flowering times of common species like orchids, mints, gentians, lilies, and iris, reports the New York Times. Henry David Thoreau is one of several note takers whose records were used in Drs. Primack and Miller-Rushing's study.