Horsetail 'buds' of some sort. Roast them
Those "buds" are the mature strobili (cones) of this ancient plant that doesn't form seeds, instead, it produces spores inside this structures (strobili) and realease them, and fly away with wind. When they fall to the ground in a place with enough water they can germinate and grow into a plant that looks different from the one that produced the spores.
Here are some photos and more information about this wonderful plant:
http://en.wikipedia.org/wiki/Equisetum
Lat: 53.37, Long: -2.00
Spotted on Apr 14, 2011
Submitted on Jul 29, 2012