Asakiyume mita

I have a love-hate relationship with milkweed. It is a deadly poison to horses so I spray it when it grows in those fields, but the stuff in my creeks, a native not-quite-so-poison version that isn't growing in the horse pastures is lovely. Local Native Americans used it extensively for fiber. It's nickname is "Indian Hemp".
Your string looks nice and even. Bet it is really strong.