First Chapter Edit
One variation of the monster is found on Milch Main Road west of Rolent and one of the quests in the Prologue, Milch Road Monster involves its extermination. Weaker versions of the creature are also encountered as normal enemies when visiting Mistwald.
Being a plant, the Pine Plant is unable to move and attacks your characters by bombarding them with Aqua Bleed arts. If the player chooses to engage the monster as soon as the quest becomes available, the arts will still do heavy damage and it's a good idea to have one character on concentrate completely on healing while the other equips an attack1 quartz and casts Firebolt arts at it, to which it is weak. The plant will go down after a few fire arts, although it will attempt to take your characters with it by exploding upon its death.
The Pine Plant is the first enemy the player encounters who self-destructs upon its defeat and causes heavy damage to all player characters nearby, which can take the player off guard if he wasn't expecting it. When facing it as a miniboss, it's best to position Estelle and Joshua in the back of the grid before the fight so they won't need to waste a turn moving out of its blast radius.
When facing it in Mistwald, the same conditions apply although since your characters are now likely at a higher level and are wearing better armor, its arts and blast damage upon death are a bit less threatening.