Can Hypno-Shroom hypnotize multiple zombies?

Hypno-shroom's upgrade includes a bar for 'zombies hypnotized'. This seems to suggest that multiple zombies could be affected by it before it disappears, but I've upgraded mine to level 5 thus far and consistently only get 1 hypnosis per shroom.

Is the 'zombies hypnotized' bar a glitch? Is it possible to hypnotize more than one zombie with hypno-shroom?

Solution 1:

'Zombies hypnotized' should be half full, indicating that it can hypnotize 1 zombie. Once it is leveled up enough, the bar should fill completely, indicating that it can hypnotize two zombies.

This is similar to the squash, which can smash zombies more than once before expiring.