Some years ago, I started collecting pictures of indigenous orchids. It is amazing what can be found in an area where one has been living for decades without noticing.
You are free to download and use the pictures. A short notice in case of commercial use is appreciated.
The download versions of the pictures are high resolution, usually 3072 x 2304, i.e. 7 megapixels.
The standard reference to the subject is the following book:
Beat A. Wartmann, Die Orchideen der Schweiz
Edition Sternenvogel 2006