By 5th and 6th, I assume you mean 'temple' and 'creeping charlie'. I can't tell what the 'temple' is, doesn't match anything in my plant book exactly. My guess would be a cryptocoryne specie. The 'creeping charlie' actually looks like bacopa caroliniana. The 'bacopa' matches a pic in my book of creeping jenny.
Alot of LFS don't know jack about plants. Many of us had to find out the same way you did, including myself. When I first started the whole plant thing, I went to the library and checked out some aquarium plant books. After realizing they didn't have the depth of knowledge that I wanted, I ended up buying a couple for myself. (overstock.com usually has pretty good deals on stuff like that).