Scientific studies are skewed toward plants with colorful and conspicuous blooms, according to researchers who argue that their new findings indicate an "aesthetic bias" in plant research.

A plant's physical features, such as height and flower color, influence its chance of being the focus of research more than its ecological characteristics or rarity, concluded the study, published Monday in Nature Plants. The authors suggest that this type of research bias could have costs for plant conservation efforts. 

The idea for the study was born when lead author Martino Adamo was writing a research paper on Tephroseris balbisiana, a rare alpine plant that he describes as "not exactly beautiful." Adamo, a postdoctoral researcher in life sciences and systems biology at the University of Torino, found little mention of this species in the scientific literature. 

"I found a lot of publications about beautiful plants, but nothing about ugly plants," he explained.

Adamo and his colleagues hypothesized that research attention would be slanted in favor of attractive plants, while plain-looking species would be ignored more often. To test this hypothesis, the team focused on the alpine flora of the Maritime Alps, a mountain range that straddles the border of France and Italy.

After choosing 113 species that are characteristic of the Alps plant community, the researchers gathered information on morphological features such as flower color, stem size and flowering duration; ecological information such as altitudinal range; and measures of rarity, including geographical range and whether the species were listed as endangered or threatened. To measure research attention, the team scoured the literature to calculate the number of studies published in the last 45 years that focused on each of these plants.

The researchers found that morphological features were the most important factors in explaining how much research attention a species received.

"The main result was that in fact there is an aesthetic bias in these publications because more publications focused on plants that are taller and that have blue or violet flowers," Adamo said. "The big surprise was that the aesthetic bias was real, at least in this area of the Alps."

Plants with red, pink or white flowers also had more research attention than those with brown or green blooms, colors that are more likely to blend into the environment.

The researchers didn't examine the reasons for this aesthetic bias, but Adamo said that tall and brightly colored flowers could grab the attention of researchers because they are more conspicuous. The researchers speculate that these flowers may stand out because the human eye evolved to discriminate between red, green and blue. Alternatively, sociocultural factors such as education, culture and upbringing could shape the way people see the world, making these plants more apparent. 

"The idea to study beautiful plants is something really human, to be attracted to something and to make hypotheses and questions about something that attracts your attention," Adamo said.

Another finding was that species with larger ranges received more research attention. Adamo said that this is likely because plants with wider distributions are accessible to more research groups.

Plants often receive less conservation attention than animals, a problem that has been called the "plant awareness disparity." As scientific research is important for informing conservation efforts, the researchers say that their finding of an aesthetic bias in plant research could tip the balance of conservation priorities between eye-catching and dull species.

As the planet is facing biodiversity losses due to habitat loss and climate change, "conservation is a very big topic at this moment," Adamo said. "Our goal was to highlight the presence of a bias and start a reflection across ecologists and conservationists on how it could be possible to overcome this kind of problem in order to make biodiversity conservation better and more efficient."

"Our publication is not meant as a criticism of our colleagues," Adamo continued. "It's just an observation." But he hopes that the study might inspire future researchers to study species that are "less attractive and harder to see."

The analysis considered the flora of just one region, so Adamo said that additional analyses would be needed to see if a similar aesthetic bias occurs in literature focused on plant communities in other areas.

The study, "Plant scientists' research attention is skewed towards colourful, conspicuous and broadly distributed flowers," published May 10 in Nature Plants, was authored by Martino Adamo and Matteo Chialva, University of Torino; Jacopo Calevo, University of Napoli Federico II and Curtin University; Filippo Bertoni, Museum für Naturkunde; Kingsley Dixon, Curtin University; and Stefano Mammola, National Research Council (CNR) of Italy and University of Helsinki.