West Sussex, United Kingdom

Memory lapse! "Black grass"
I've split the plant up into 7 and have potted them up to deliver to a charity shop tomorrow, but I want to label them. I know it isn't a grass although I thought it was until recently. It's just like a tuft of grass, but black, and I simply can't think of the name. Sorry I haven't a photo. Hope someone can help. Thank you.

• 12 Jun, 2017