I’m repeating myself, I’ve noticed, but it’s ok. Turns out that after I decided today that it was time to post a photo of this lovely flower (click for larger view), I noticed that I’d done exactly the same thing last year, on the same day. It’s the first of the buddleia (budlea) flowers to bloom in the garden, and it’s always a welcome sight. It takes a number of days to reach its peak, more of the little sub-flowers opening up each day until the whole thing is exposed. The smell is wonderful, and the butterflies that are attracted to it seem extremely happy about it. As am I.
-cvj
I’ve noticed that a very large number of wild flowers are similar in colour to the buddleia in the photo, so maybe purple is particularly attractrive to insects. I’ve seen a really good range of butterflies this year on recent walks. My buddleia is yet to flower so maybe we’ll have loads of butterflies in the garden too later in the season.
Hi,
Yes, Hydrangeas are quite remarkable for their colour changes as a result of soil. It’s quite well known in England (at least….I don’t know how commonly they are used in gardens here in the USA). I do not know if buddliea are like that. This plant is different from the one I shot last year. I don’t know how much variation there is plant to plant.
I don’t know about insect responses. Perhaps they respond more to colours that we cannot see, and those don’t change as much? Or maybe scent is far more important in the attraction process. I don’t know, but I suspect evolution took care of it, given that the plants are here. Maybe some google searching will turn up the answer…
Cheers,
-cvj
Last year, the flowers look fairly pink, but this year they are nearly violet or blue towards the edges. It could be due to the photography. The appearance of colours is a sensitive function of the light spectrum which is illuminating them. This year the photo was taken in sunlight, while last year it looked more overcast. Or maybe the exact colouring composition in the plant depends on environmental factors such as the recent temperature changes or the amount of moisture in the soil.
According to http://www.uri.edu/ce/factsheets/sheets/hydrangea.html , for Hydrangea macrophylla: “color is dependent upon the pH of the soil in which it is grown: blue if acid; pink if alkaline.”
I don’t know whether soil pH is a factor determining colour for buddleia, but if it is, then moisture variations would affect colour since a lot of rainfall would dilute the acidity or alkalinity of the soil. It’s interesting if pH is a factor determining flower colour. Obviously for lichens such as litmus, you’d expect colour to depend on pH. But for flowers, you’d expect the plant – as a result of millions of years of evolution – to minic the chameleons and so be the best colour for attracting the right sort of insects for pollination, instead of responding in a sensitive way to the acidity or alkalinity of the soil.
Maybe the flower does change colour in response to the changing insect population in the different seasons?