Taxonomy key value in multilanguage site

Hello,

I have got defined a multilange site with this as taxonomy:

language:
      de:
           taxonomies:
               product: "Produkt"
      en:
           taxonomies:
               product: "Product"

in my index.html I’m iterating over the taxonomies

 {{ range $taxonomyname, $taxonomy := .Site.Taxonomies }}
{{ end }}

How can I get the key “product” within the range loop? $taxnonomyname shows only the translated value of the taxonomy “Produkt” or “Product”, but I need the key value, how can I get this?

Thanks