Can treesingers plant shape into their companions?

[Doomey]

The plant companions are plants correct? So the treesinger can use their wildshape to change into their companions plant types yes? Also, the treant companions double damage to objects ability is very vague, does it work like it's larger counterpart?

[Mighty Squash]

The polymorph rules would say you can only shift to being a Bestiary standard version of the plant creature, not a companion version.

There are other druid archetypes that seem to suggest this is not the case however (such as Eagle Shamans being specifically told they can wildshape in to a roc but bestiary rocs being too large for a druid to ever shift in to, while the companion versions that fill the gap perfectly but break polymorph rules).

[blackbloodtroll]

Are there "standard" versions of the plant companions?

[Mighty Squash]

I was too lazy to look them up (and still am), possibly no

[Doomey]

Not for the puffball, carnivorous flower, crawling vine or sapling treant. The text in the plant shape spell doesn't state it has to be out of the bestiary, just that it has to be a small or medium plant.