P. vialii is a rosette-forming herbaceous perennial to 40cm. Come mid June, flower spikes rise up to 2 feet (50 cm) from the clumps and open to show a stunning display or red cones covered in tiny purple flowers.
This is a truly striking plant and I have seen it used to great effect in a fantasy cottage garden with hostas, ferns and Astilbe chinensis ‘Vision in Purple’.  Also seen in our local Hillsborough Castle Walled Garden looking spectacular