Sanctioned, and Unsanctioned

Or did my memory do a major nosedive? I'll explain:

Below is the perfectly good, expected even, result of planting a rhizome in spring. Helenium "Moorheim Beauty" gradually emerged from the ground and commenced blooming with dusky red flowers that turn a little golden as they age.

The blooms remind me of echinacea with their recurved petals, and I'm happy with the warm color. They're another in the MulchMaid's theme of simple, flat flowers.

But what IS this growing so apparently legitimately right next to it?

The leaves on this bruiser are about fourteen inches long, and they have the most fascinating small hooks set into the upper surface.

I've been waiting for some sign of a flower spike or stem, but nothing new is showing after months of growth.

I keep thinking this must be something I planted as a bulb or rhizome early this spring and have just blanked on. So far, it's not giving me any clues, just more small, hooked leaves. Since I moved a few things around in that bed, I could even have accidentally moved it myself.

It's pretty interesting, and so healthy I hope it isn't some major garden marauder weed. For now, I'm willing to give it some space, and see what develops.

Of course, if you recognize it, do let me know.