the cactus puzzle

[herio]

its a cleve puzzle but theres no fead back so its frustrateing can i sugest for next time or poslby pach the gard to give a hinit how wrong it is eg this is no were near the the cactus or if your close the the cactus has more or less spikes or someting just a hint

[Ashraz]

Just make some notes while the guard tells the names of the (non-)similar cactus, e.g.

Looks like

• name of the first
  
• name of the second
  
• name of the third

Doesn't look like (at all):

• name of the first
  
• name of the second
  
• name of the third

Then have a look at the poster behind the guard.

[Hunttako]

Straight spines
Four flowers
Y-shaped body
Six spines
Maurice