Researchers at the University of Prince Edward Island are trying to figure out why purple is the dominant colour amongst the lupines that line P.E.I.'s roadways.

Lupines come in purple, pink and white, but most are purple. UPEI biology professor Karen Samis wants to know why.

The research started last year, and already has come up with some surprising results. As expected, Samis's team counted far more purple flowers, but she was surprised to find the pink-flowered plants produced far more seeds than the purple ones.

Samis has a number of theories about why this might be.

"There are a variety of reasons, but to be honest, we don't know," she said.

"Our goal this year is collect more data to tease out some of those possible reasons."

The impact of predators is one theory Samis is working on. It could be purple flowers are being attacked by predators so that fewer seeds are produced. Samis will also experiment with planting seeds from pink and purple flowers to see which are more likely to grow.

Bees could play a key role in the mystery, and Samis is looking into their behaviour around the flowers. Researchers constructed mesh casings to go over some young lupines in order to block access to bees, to see whether bees are needed for pollination, or if there is another mechanism.

They have also been tracking bees to see whether they are targeting more purple flowers than pink or white ones. Researchers are curious to see if bees will stick to one colour of flower, or switch between colours while visiting a lupine patch.

Seeking public's help

While Samis's research clearly shows there are more purple lupines now, she would also like to know if this has always been the case.

She's looking for the public's help in answering this question. She's asking for people to send in old photos of lupines, along with the date and where they were taken. These pictures will be examined to see if the proportion of purple lupines has changed over the years.

The photos can be submitted online.

For mobile device users: Do you wonder why there are so many purple lupines?