Lycopodium japonicum, common clubmoss.
If you sprinkle the spores over a flame they spark in the air as the internal oil burns.
They used to be collected to use as yellow powder during Holi, now replaced by yellow aniline dyed powder - which is mildly carcinogenic, like so many of our modern chemicals. [mind you, spores of Pteridium revolutum, Bracken, are carcinogenic, too, so it's not only modern unnatural chemicals!].
As I expect you have seen, the plant is traditionally used to adorn wedding gates at marriage-parties - and even the army use it on their barbed-wire fences - which is not sustainable and ought to be stopped. I have seen people gathering great sacks of it for sale as an adornment. It can't be cultivated as it always dies once uprooted, wrong mycorrhiza...
Best wishes,
Chris Fraser-Jenkins, Portugal.