That's 'Equisetum' in Latin, and it's a native plant in most parts of the world except for Australia, or so I have read. There are other varieties of Horsetail in the world that grow really tall, up to 8m, but this is the 'wee' variety! Common along the lanes here in Northern Ireland and the rest of the UK.
I'm going back a little to around the middle of July with this picture. I wouldn't bother trying to dye with the plant after the end of Summer as it's dye value will be a lot less. It's a weed frankly, and I wouldn't give it space in my garden as it's hard to get rid of. It actually sprouts up through the tarmac drive. I even sprayed it with a noxious chemical but it lived on. So what to do? Well, apparently it's edible, but only if you are starving. So in the pot it went for dye. .....
Nothing scientific going on here. I crammed the pot to the very top (as you do), just over l pound of plant material and covered with water and simmered for an hour. Actually, after it started to heat up and the plant started to squash down, I added more until the pot wouldn't take any more, then crammed on the lid. Resulting dye bath was rather a good yellow as you would expect from so much plant, and added a pound of clean, wet, pre-mordanted (Alum and cream of tartar) very soft and fairly long-staple, hog fleece, and simmered a further hour. I will be trying after-mordants another time, but I like the clear vibrant yellow just as it is. In fact this is one of the best yellows I've ever dyed.
Because I can achieve such brilliant yellows out of the hedgerow, I don't grow yellow dye plants in my garden such as Weld which is a space-hungry plant and sheds its seeds everywhere and just keeps popping up amongst the carrots etc. The only yellow giving plant I'm tempted to grow is goldenrod as the yellow is exceptional, and it doesn't grow wild around here, but the hedgerows here abound with dyers broom, and other yellow-giving plants.
Just in case you are wondering, it's this same wool I'm spinning in the Video
and is also featured in the photos on my new greetings cards for sale on facebook. There are also pictures up there of this wool being spun via my 'pictures' tab on Facebook
This is it spun up fine for Shetland knitting, at around 15 wpi, but I've also incorporated it into some art-yarn which you can see in my 'handspun wool' posting.