Its kinda pointless asking if a lens fits whatever purpose if you don't state what your camera body is.
that being said, i shoot a lot of landscapes, most of my pictures lie in the 24-30mm and 175-200mm range on a FX body. I wouldn't recommend a 50mm (75mm on a DX crop) as a landscape lens. you can still use it though.
edit: i'm also pretty obsessive when it comes to grammar... the word 'lens' is singular. the word 'len' refers to something entirely different.
I don't see why not as for 'Landscape' what will be the main:bigeyes:concern is the "Framing/composition" of the pics that you wanna achieved and not necessary all you 'Landscape' shots will only come out in Wide-angle views, right??
When you do your 'Landscape', just use your :bigeyes:Eyes to/and picture/imagine the scene/things/items that you wanna include within your 'Frame/in-the-picture, and those scene/things/items you'd like to exclude from your 'Frame/from-within-your-picture'...you see it...got it now...??
So pretty much that any focal-length also possible...