Today I photographed a plant on a waste field and found a perfect match with the pictures on this French site:
It says: Medicago sativa subsp. media
and when looking at the long list synonyms they give; I see quite a few which are entered in our database..
Now, I am not entirely sure if I can take this serious looking site as an authority or not..

http://www.florealpes.com/fich...
http://www.florealpes.com/sele...

http://garden.org/plants/searc...

There are lots and lots of synonyms in Medicago.

http://www.theplantlist.org/tp...

Do we need them all listed in our database? It would be good to have them but I don't think it's a problem if we don't. Many of those synonyms are unresolved with low confidence.

I personally don't think it is necessary to have that huge list of synonyms in our database, but I still don't know if I can add Medicago sativa subs.media like it is named on the French botanical site..as that name is not in the database yet? I seems to be a natural hybrid between Medicago falcata and Medicago sativa. My botanical book (which is quite old dating from around 1950) says: Medicago falcata x sativa..

The only online reference I can find to Medicago sativa subsp. media is that french site your referenced, along with a few other french sites.

I would probably say listing the species as "falcata x sativa" would be safer.

OK got it Dave!

Dave when I typed in : Medicago falcata x sativa in the search box:
it gives me this:Medicago sativa subsp. falcata.:
http://garden.org/plants/searc...

I found out when I entered it under Medicago falcata x sativa it got accepted!

Actually, it appears that your plant is Medicago sativa subsp. varia http://www.ildis.org/cgi-bin/A...

Under that citation is the common name in French of Luzerne Bigarree which is the same as that listed in the original post http://www.florealpes.com/fich...

Interesting in that it's a hybrid but considered a sub-species because it appears independently in many geographic regions.

Thanks for that, Monica. I edited the plant.

Medicago sativa subsp. varia

Thank you Monica! Nice to know too that that French site seems to be reliable!