Spike Stones / Growth...It's a trap?

[Lochmonster]

Just what the title says, I am confused by the wording of the spells Spike Growth and Spike Stones. Here are some specific questions:

1) It says Rogue but I assume anyone with the disable device skill or the ability to find magical traps can sense these, is that correct?

2) Once someone walks over a 5 foot square of spike stones/growth is it then "set off" and obvious or does it require a perception check still?

[Lochmonster]

BUMP

[Artanthos]

The spell was written prior to other classes gaining access to trapfinding.

Spike Growth wrote:

Magic traps are hard to detect. A rogue (only) can use the Perception skill to find a spike growth.

RAI: the spell is restating rules that existed at the time it was written.

RAW: sorry urban rangers and cryptbreakers, your out of luck.