The most famous of Madlener's paintings is Der Berggeist ("the mountain spirit", cf.
Zimmermann (1983:22) interviewed Madlener's daughter Julie (born 1910), who distinctly remembered her father painting Der Berggeist sometime after 1925/6.
She also noted that the postcard version was "published in the late twenties by Ackermann Verlag München, in a folder with three or four similar pictures with motifs drawn from German mythology: a fairy lady of the woods, a deer carrying a shining cross between its antlers, 'Rübezahl', and possibly one more".
The whereabouts of the original was unknown for some sixty years, until it was auctioned on Sotheby's in July, 2005, and sold for 84,000 GBP.
A monograph by Eduard Raps (1981) published for the artist's centenary, shows many examples of Madlener's art.