Flowering perennial

Flowering perennial

Observation - Flowering perennial. Description: Largeish herbaceous perennial in a garden setting. Leaves opposite, finely toothed: they look rather like Lamium orvale but a much brighter green. Flowers in spikes, opening from bottom up, zygomorphic. I don't think I've seen this before, and wo

Largeish herbaceous perennial in a garden setting.

Leaves opposite, finely toothed: they look rather like Lamium orvale but a much brighter green.

Flowers in spikes, opening from bottom up, zygomorphic.

I don't think I've seen this before, and would welcome suggestions.