if they happen to have the same plant available in the actual plant tank, you should get it from there instead (they usually have large supplies of the general standbyes, such as wisteria, hornwort, primrose etc) since they'll usually be healthier than the ones in the tubes.some of them (most swords and ferns etc) you'll have to use the tubes, since they take up more room and therefore more "retail space" and hence usually aren't planted in the tank. steer clear of the "plant bundle" ones, though, they're notorious for having large quantities of non-aquatic or semi-aquatic plants that will do nothing but die and then poison your tank as they decompose unless you're set up to plant them with emerged leaves.
So remember, when you're feeling very small and insecure,
How amazingly unlikely is your birth,
And pray that there's intelligent life somewhere up in space,
'Cause there's bugger-all down here on Earth.
Loki/Grendel/Gail/Beowulf/Camilla/River/Bathory/Arwen/Lafayette/Deb/Jack Skellington (soon)