There are two of them, Croad and German. To my knowledge, the German Langshan is the one that is not in the US. The Croad is the only accepted version and is known only as Langshan in the U.S. Only in the UK are there two recognized versions.
Croad Langshan (UK) and US Langshan are generally thought to be one and the same:
Here is a photo of a German Langshan to show the difference:
Croad Langshan (UK) and US Langshan are generally thought to be one and the same:

Here is a photo of a German Langshan to show the difference: