Steel veins stretching across vast lands, guiding iron beasts to distant towns, where whistles echo in the morning mist.

I can be Dutch or French, among others. Wheel or wedge, or grated for all that matters. I can have mold but don't throw me away. Not all mold is bad per se.

I can be a support, hold things together, or help open and close. I enclose words in a sentence or symbols in an equation. In March, you might join the madness and fill me out.

Grow in caves from the ceiling, Slow I am made by water dripping.

Arr matey, a wooden home for treasures untold, Stacked high in the hold, like gold they enfold. Ye'll find these in the galley, or on the deck, Hoist them up, and mind yer neck!