Greater Quaking Grass (Briza maxima)
Last year we visited an ex-colleagues garden when it was open under the open garden scheme. The Quaking grass self seeding at odd spots in the gravel drive attracted Clickychick's eye. There were various plants on sale for charity so she bought a quaking grass thinking the odd one self seeding in our gravel path would be attractive. I am sure the odd one would have been very attractive. The problem is we don't have the odd one, we have a patch about 1.3m by 0.3m (4ft x 1ft). This is after some fairly heavy weeding.
Greater Quaking grass is basically a mediterranean plant but it does very rarely occur in the wild in this country. The more usual Quaking Grass in UK is Briza media not listed as uncommon in my reference books. However I have only every known it grow at one place and they seem to have disappeared, victims I suspect of road alterations.
As an aside I grew up calling this grass in my native tongue (Cumbrian) dathering grass.