Plants picked by Victorian collectors up to 150 years ago are a valuable new source of data for ecologists seeking to understand how climate change will affect the timing of flowering plants.

Scientists have used the carefully labeled and dated specimens of the early spider orchid, Ophrys sphegodes, to examine the affect of spring temperatures on flowering. The flowers were collected between 1848 and 1958.

The results, published in Journal of Ecology Sept.21, found that for a 1.8 degree Fahrenheit increase in the spring temperature, the orchid flowered 6 days earlier.

The results are nearly identical to field observations collected between 1975 and 2006. The fact that the response to temperature changes has remained constant, despite accelerated temperature increases since the 1970s, lends support to the use of museum specimens for climate change studies.