It looks like one of the Nutsedges; Yellow Nutsedge (Cyperus esculentus) or Purple Nutsedge (Cyperus rotundus).

Is the flower stem triangular?

Thanks for your quick id, after you said sedge did some image searching it is surely yellow nutsedge. I snipped one of the main stems though the scissors deformed it a bit it is 3 sided. Tasting the larger roots with the tip of my tongue, yes I'm aware the mr. hide aproach to plant identification isnt a good idea, reveals an a mild nutty flavour overshadowed by an alkaloid taste. Now I know what stole all the nutrients from my neglected arugala patch.

Thanks again.