Invasion

We learned yesterday that the managers of the Eastern Yar, along with many other such groups, have deemed the Himalayan balsam (Impatiens glandulifera) which particularly favours its riverbanks, an invasive pest which needs to be eradicated. In 24 hours I had forgotten the second half of its name, but Google Images soon put me right.

I learn from reference 1 that it was introduced to this country at about the same time (1839) as Japanese knotweed and giant hogweed. I also read what sounds to me like a rather far-fetched claim that the idea was to introduce flashy flowers to the masses, who could not afford the flashy orchids that the gentry went in for.

Then today, I notice a number of other wild flowers which were pretty much the same shade of pink - which prompted me to wonder whether anyone had analysed the distribution of the colours of flowers  by species, by acreage or anything else. Is there just some modest number of petal dyes and that it your lot? Or does the plant world do the equivalent of the paint mixer at B&Q, and is able to knock out any colour that you care to specify, by RGB value (as in Microsoft products) or otherwise?

My bet is that if you did it by acreage at the right time of year, yellow would win: there is an awful lot of sunflower and canola (what rape seed oil comes from) out there.

Maybe exclude things like grasses from consideration: only regular flowers with proper petals count. 

PS 1: Gemini is not having the Wikipedia claim, and without checking further I am inclined to agree with him. Not often that I find glaring errors of this sort there.

PS 2: and on colours he goes for white then yellow then pink. Without any proper statistical qualification in the first instance. Maybe I shall dig deeper.

PS 3: a little digging and I turn up references 2, 3, 4 and 5, all open access and all of which appear to bear on the distribution problem in one way or another. With a start being reminded that the pollinators to whom colour might be an important signal may not see colours in the same way that we do. Maybe I shall take a proper look tomorrow.

PS 4: the following morning produces the figure above from reference 4, an analysis at the level of the species, drawn from a database of  some 10,000 species. We do not seem to be told anything about how these 10,000 were selected from the much larger number of flowering plants in total. On the face of it, if we exclude green flowers, Gemini was right: white then yellow then pink. However, it is not clear to me that species is the right unit of analysis. Nor is it clear what might be better!

This database appears to be the TRY database of references 6 and 7. Which appears to know a lot about flowers if the snap above is anything to go by and flower colour, the fourth trait, gets good numbers. I think the database is open access, but not online. One has to submit online requests for offline execution: not quite the same as asking Gemini. Noting in passing that the number of species for flower colour, 10,587, is very close to the slightly older figure offered by reference 4.

References

Reference 1: https://en.wikipedia.org/wiki/Impatiens_glandulifera.

Reference 2: Primer: The evolution of flower colour - Roman T. Kellenberger, Beverley J. Glover - 2023.

Reference 3: Abiotic factors may explain the geographical distribution of flower colour morphs and the maintenance of colour polymorphism in the scarlet pimpernel - Montserrat Arista, María Talavera, Regina Berjano, Pedro Luis Ortiz - 2013.

Reference 4: Fragmentary Blue: Resolving the Rarity Paradox in Flower Colors - Adrian G. Dyer, Anke Jentsch, Martin Burd, Jair E. Garcia, Justyna Giejsztowt, Maria G. G. Camargo, Even Tjørve, Kathleen M. C. Tjørve, Peter White, Mani Shrestha - 2021.

Reference 5: Flower color phenology in European grassland and woodland habitats, through the eyes of pollinators - Sarah E.J. Arnold, Steven C. Le Comber, Lars Chittka - 2021.

Reference 6: TRY plant trait database–enhanced coverage and open access - Kattge, J., Bönisch, G., Díaz, S., Lavorel, S., Prentice, I. C., Leadley, P., et al. - 2020. A paper with a very large number of authors, perhaps everybody in some large research organisation.

Reference 7: https://www.try-db.org/TryWeb/dp.php.