Xanthium seeds?

[Lisbeth Jonsson]

Dear collegues,
We have run out of our source of Xanthium pennsylvanicum, cocklebur,  which
is such a nice example to demonstrate photoperiodic control of flower
initiation.
Now we are looking for new "burs", and the seed companies in Sweden have
not been of much help.

We would be very grateful for a suggestion of where to find Xanthium seeds!

Thank you very much in advance for your help,
Lisbeth Jonsson

Lisbeth.Jonsson at vfys.slu.se

Dr.Lisbeth Jonsson
Department of Plant Physiology
Swedish University of Agricultural Sciences
P.O. Box 7047, S - 750 07  Uppsala
phone +4618671496 fax +4618672930