What are the differences between 床,　床上, and　床の上?


I think I have an idea of the differences but I'm not sure. My goal was to say
"put [something] on the floor".

To me, `床{ゆか}の上` sounds the best (not that means anything). For example:
`服を床の上に置きます。`

The dictionary definition of
[床上{ゆかうえ}](http://kotobank.jp/word/%E5%BA%8A%E4%B8%8A) is `建物の床の上。また、床から上。`.
It looks it has more of a "above floor level" or "from the ground up" meaning,
but I still see the English translation of "on a floor" (i.e. Rikaiちゃん). Is
this misleading, or would something like `服を床上に置きます` work?

Lastly, where would just plain old 床{ゆか} fit into this? Does it have a
connotation of the floor or a bed? Is it ambiguous if I just said `服を床に置きます`?
(If so, does 床の上 not have that ambiguity?)

Bonus Credit: Have I missed anything that means "on the floor"?




I don't see much difference between [床]{ゆか}に置きます and 床の上に置きます. (I think I
normally say 床に置く or [下]{した}に置く in daily conversation.)  
I don't think you say [床上]{ゆかうえ}に置きます. I think I hear/see [床上]{ゆかうえ} in
[床上浸水]{ゆかうえしんすい} or 床上まで水に[浸]{つ}かる etc. (often on TV or in the newspaper)  
  
I think [床]{とこ/しょう} as "bed" is normally used in (a set phrase? like)
[床]{とこ}に[就]{つ}く, [床]{とこ}に[入]{はい}る, [病床]{びょうしょう}, or [病]{やまい}の[床]{とこ}...

