Photos contributed to HMF must either be your own or you have permission from the owner to use them. It is not uncommon for nurseries to grant HMF permission to include their photos on the site.

You are absolutely correct that I neglected to repeat in my comments what the photo itself already states: that the photo comes from Poulsen. However, you are not correct that the photo is used improperly on HMF. Poulsen expressly provides a huge selection of photos of its roses for public use. In the case of HMF, the use is to describe Poulsen's own product line. This is exactly what Poulsen's website says:
"How to get the pictures of the products? If you need a good picture of a rose for your article or just as an illustration on your homepage or in your presentation, you have here at the market place access to all our digital pictures for you to search among. You can have a look at the pictures and download them in low resolution. If you require high resolution pictures you can order them directly from our homepage." In addition, "In the image archive you can download low resolution images for use on the internet or in presentations. You can limit your search by choosing from the 5 menues above. Thereafter, click on "Search" to list the images according to your search criteria. Click on the individual images to see them in an enlargened version or click on the file name to download the image."

I hope that this clarifies HMF use of Poulsen's images. They are used with express permission of Poulsen Roser A/S. Some other rose producers have similar policies.