Weed or not?

[WPG]

From the looks of it, bugle is what my 'mystery plant' is too. I was given this small nameless plant last spring, and potted it on to see what happened. Within the space of a year it's grown this much - nice in the pot, but looks like it'd be quite invasive in the soil.

[alldigging]

I've been told I need to get some grass seed to repair the gap in the lawn when I move it.