To put it in simpler words, it was a test for Ajax whether he was an alchemy master or not.
As long as he was even a rank 1 alchemy master, he could tell the uses of a rank 2 herbs.
"Sure,"
When it comes to the information of pants below rank, Ajax could say them as long as he knew the plant's name. So, he looked at the rank 2 plant behind the green sprite.
"Plant name, Knum. Rank 2 medicinal herb,"
With a glance, Ajax was able to tell the plant name and closed his eyes to search for the uses of that particular plant.
Ajax's alchemy knowledge came from three things.
First one, he assimilated the alchemy king's basic handbook which contained all the data of plants and herbs of rank 4 and below.
The second one, he also used Mason's family pill book which contained all the techniques and other plant-related stuff in it.
Lastly, the system sent the knowledge of all the plants of rank 4 and below into his head.