1/2 Mark Verein Naturschutzpark/Heidepark

The Verein Naturschutzpark, founded in 1909, was one of Germany's earliest organized nature conservation societies, dedicated to preserving heathland — particularly the Lüneburg Heath — from agricultural enclosure and industrial development. During the hyperinflationary crisis of the early 1920s, municipalities, businesses, and civic organizations across Germany issued their own emergency currency (Notgeld) when official small denomination coins vanished from circulation. That a conservation society found itself in the business of printing fractional currency is a small but telling symptom of how thoroughly the Reichsmark's collapse had disrupted daily commerce.

The DeNG reference distinguishes two varieties (.1 and .2), suggesting at minimum a paper stock or overprint difference between print runs.