What wild plant (grass?) is this

[Ratatoskr]

This plant was photographed 6th of June of this year. It grows in an old field that in the 70's used to inhabit cows but is now overgrown. It's at least around 1 meter tall. The location is scarcely populated.

Thanks for any help on species or genus.

[Ferret]

I think it’s a Sedge, and probably the genus is Carex.
You will need to know the shape of a cross section of the stem, the shape of the ligule(where the leaf leaves the stem), the shape of a single fruit, the shape, length, colour and possibly the shape of the tip of the leaves, the number of male to female flowers and whether they are on the same stem. That should get you started, you will probably need a good hand lens and above all a good guide and key to the sedges in the part of the world this picture was taken.

I hasten to add I am no expert but have just started trying to get my head around these plants in the UK.

Ferret

[Ratatoskr]

Thanks Ferret,
You helped me feel sure of it being of the genus Carex.

A few botanists have replied to me and all are on the same page when it comes to the genus, ie Carex.
My first response I got on a botany forum was Setaria, but that did not look or sound good to me after researching that genus, so I sent mail to the foremost botanists in Sweden and they came up with what you told me too. My forum post here was entered at the same time as I sent the mails to the experts.
One of them is the explanation I'm going with and he says it may well be a hybrid from either Carex riparia or Carex acutiformis.
He of course had only what I told him to go on + this the same and only photo which as you can see is missing a LOT of info.
I will have to check the plant again next autumn.