If there's one thing that Kiwis love it's a good sarcastic name. This one is not really a grass, it's a sedge, but it looks like grass so the wide variety of these hook sedges in New Zealand are called "Bastard grasses".
The name is not meant to be polite, but it is kind of funny. The first time I saw this particular one and found out it is called Zotov's bastard grass I was definitely amused.
They are called bastard grasses because the hook on the tip of the seed is just perfect to catch on to hairy legs or arms or on sheep's wool. If it gets in wool the wool is ruined, hence the less than polite sarcastic name! They are also called hook grasses or hook sedges, but most commonly bastard grasses.
Carex zotovii is not super common in New Zealand, but we do have lots of it around Karamea, so it's a bit of a hot spot here. The plant is named after After Victor Dmitrievich Zotov (1908 - 1977), one of New Zealand’s most eminent botanists.
For more info see Carex zotovii | Karamea.nz