Sorry not sure what you mean. I'll check the plant codex and get back to you... Here are some screen shots to help explain.
Datacron has already been activated
http://i211.photobucket.com/albums/bb70/andcbii/SWTOR/Screenshot_2012-02-23_21_24_02_957152.jpg
No codex entry.
http://i211.photobucket.com/albums/bb70/andcbii/SWTOR/Screenshot_2012-02-23_21_24_20_480154.jpg