geff.2007's picture

Alpine Knapweed Seedhead

Observed: 4th June 2011 By: geff.2007geff.2007’s reputation in Plantsgeff.2007’s reputation in Plantsgeff.2007’s reputation in Plantsgeff.2007’s reputation in Plantsgeff.2007’s reputation in Plants
Knapweed, Alpine (Fruit)
Description:
Identifications
Species interactions

No interactions present.

Comments

martinjohnbishop's picture

Why not Centaurea scabiosa?

According to the Flora Helvetica there are 21 species of Centaurea in Switzerland. I am not convinced you can identify the species from this one photograph.

geff.2007's picture

Knapweed Seedhead

As I stated "It might be this". Unfortunately my system does not record where or how I came to this identification. Certainly I don't have access to such learned tomes as you quote which is why I find iSpot so useful. I do like to try and identify items before adding them and this one struck me as being somewhat different. Maybe it is not possible to make an exact i.d. just from a seed head.

martinjohnbishop's picture

The appendages are like C. scabiosa

at 1-2 mm across and too delicate for C. alpestris.

I do not have access to Flora Helvetica either, just googled it. There are more then 200 in Flora Europaea which I do have. I find them a difficult group for which many characters are needed. It says (for the involucre which is all we can see):

C. scabiosa Involucre 18-25mm ovoid globose; bracts 3-4mm wide, ovate, numerous, glabrous or arachnoid; appendages 1-2mm x 1-2mm , not covering the bracts, triangular-ovate, brown or black, decurrent with light brown fimbriae.

http://crdp.ac-besancon.fr/flore/Asteraceae/especes/centaurea_scabiosa.htm

C. alpestris Involucre 20-40mm ovoid-globose;
appendages c5mm, ovate, completely covering the bracts, broadly decurrent, the fimbriae dark brown.

http://crdp.ac-besancon.fr/flore/Asteraceae/especes/centaurea_alpestris.htm

geff.2007's picture

Centaurea

Thanks for that MJB - maybe the light brown fimbriae are the answer making it scabiosa. Keep up the good work! Anyone else going to enter the debate?