HEATH SPOTTED ORCHID Dactylorhiza maculata ssp. ericetorum Up to 40cm high with up to 50 flowers in the warm south of the UK, can be much shorter and with far fewer flowers (5-20) elsewhere. Tends to grow in clumps. The flower spikes tending to be conical (or 'pyramidal' if botanists must).
I actually thought to take a picture of the description of this plant so I could pass it on, which is unusual for me. It's called a White Bat Flower (Tacca Integrifolia), Cat's Whiskers or Devil's Tongue.