I took these the other day but now I'm trying to decide which Centaurea this is. Both pictures are of the same flower. TKS in advance Charles EDIT: Just added 3 more images
Wow, does anyone vist this forum. Under the old identification forum I used to get an answer in minutes, sometimes hours, but sledom longer than that. Charles
I have some other pictures from the local botanical garden (jardin botanique de Neuchatel) of Centaurea montana and they look quite different. I'm thinking Centaurea jacea or Centaurea scabiosa. Charles
I went to the library today and after looking in 5 books, I still wasn't sure which Centaurea this is. My next stop was the book store. I did find a book that clearly shows the difference in the leaves of these two Centaurea. The leaves look nothing at all like the leaves on a scabiousa so if I have to pick between the two I'll go withj jacea. While there are quite a few different Centaurea, they don't seem to match as well as Centaurea jacea. Comments welcome Thanks
Hmm! I think it rather depends on the post. Had you posted just pics, you would have probably had an answer of Centaurea in minutes. In this case you want to know which Centaurea this is. Much bigger problem! Which is why I haven't posted In the RHS Plant Finder 2010-2011 it has a list of 91 different species and cultivars. I love these and grow several. However, 2 pics do not give enough info for even the most passionate Centaurea fan to pin it down with complete confidence. For example. I have one called C.Bella. It looks a little like your pics. However, I know from experience that the plant is a dwarf with a low dome of leaves and flowers rising 6" above the leaves. When taking pics for id, it sometimes helps to see a picture of the whole plant, also flowers and leaves. Even colour sometimes counts. Which as your 2 pics show is a problem, as cameras can alter colours. Mine does especially in the blues. Even books cannot always help, as few will show ALL 91 that are currently grown/ sold in the UK.... with at least 3 pics for every plant, to enable a comparison.
Agree it isn't too convincing for C. montana, which is why I was dubious in my post. But equally, it isn't C. scabiosa either, as that has deeply pinnately lobed leaves, nor C. jacea, as that has much less pronounced differentiation between the large outer florets and small inner ones. I guess I can really only echo Silver Surfer's points - there's lots of them, and detailed information isn't easy to get. Have you tried asking the Garden's staff?
Thanks for the replies, I think I now see the problem more clearly. Those are not cultivars but I guess they could be escapees. Wild Centaureas are very common here in Switzerland and are in bloom a good part of the warm weather. First down on planes where this was taken, then progressively higher up. I'm aware of the color shift but I'm not sure how to solve this. I've looked at some of the professional online garden libraries and they seem to suffer the same problem; color shift. I have over a hundred photos of this plant from the same shoot so I'll look to see what others might help with the ID. I chose jacea, scabiosa, and montana because they are the most likely wild Centaureas in the area. But, as you said, with 90+ varieties, it does become difficult to identify. I hope I didn't sound ingrate. The people here on UBC have always treated me nicely. I am grateful for the responses in more than just the short term goal of identifying a plant or flower. I adjust my photo style based on the feedback I get here. In the past, I might only shoot the flower head. Now I'm trying to make sure that I get a shot of the leaves as well. But now it looks as though I need to try harder to get a reference shot of the whole plant and a distinct shot of the leaves including how they join the stem. I took a short break in the middle of writing this response and it came to me that perhaps I need to shoot a gray card and possibly a white card so that I can accurately set the white point. Perhaps by taking a reference shot with a pure white card I can be â little more certain of the true color. Any feedback or pointers on how to take better photos to aide in identification is surely welcome. I think that there might even be a need in the ID forums to have a sticky topic on how to take reference photos. It might help people that like doing the ID and it would help people asking for an ID. Anyway, thanks. I have to go attend to other stuff right now, but I'll attach an additional set of images later today. Charles
hi Charles, i think that it will be impossible to get a definitive identification from your photos. I have no idea of the total number of species of Centaurea, but there are 25 species in Portugal alone and I guess more than 100 in southern europe. Many of the species are very similar in appearance and are distinguished mainly by the appearance of the involucral bracts. ...but the best of luck with the attempt ! Brian
I just added 3 more images. They not significantly different so they probably won't help. I looked through the images I took that day and there isn't any showing the full plant. I might get back over there this weekend but the field is scheduled to be cut for fodder when it gets dry enough. It rained all week so it probably hasn't been cut yet. Charles
Charles, if you get the chance, do collect and photograph some of the involucral bracts! good luck Brian
Well I finally tried to use the Flora Helvetica, the definitive guide to Swiss Flora. Not an easy reference to use. According to the Flora Helvetica there are 21 species of Centaurea in Switzerland. Of those, 6 are white or yellow. So 6 down and 14 to go. :) Charles
Here's an additional photo showing the involucral bracts. I think this just about exhausts my supply of photos of the Centaureas that I took the other day. Charles
hi Charles, Sorry for delay in replying. I am afraid that you need a photo of the detail of an individual bract. But i am sure that the flora will give you other points to look out for as well. good luck Brian
