Plant
Us plants, are neither Darkners nor Lightners.
We are living beings...
...that take on new consciousness in the dark.
Plants are a class of beings in Deltarune. In the Light World, they appear as normal plants; however, in the Dark World, they are given sentience and a new form, akin to but distinct from Darkners. Currently, none can be recruited.
In the Dark World, a plant's color scheme is influenced by their Light World form's colours. Unlike Darkners, though, their real-world inspiration is more loose, as their personalities, appearances, and bullets are much more removed from their Light World forms. Coincidentally, the six colored flowers in Chapter 5 have personalities and bullet patterns based off the same-colored SOUL in Undertale.
For dialogue, plants may have no portrait, a colorless portrait similar to Lightners or a symbol in place of the standard asterisk; in the latter case, the color of the text and symbol is also changed.
In the Dark World, plants can live lives as if they were a Lightner as well as partake in encounters. They are capable of using magic akin to Darkners, being able to cast bullets.
Plants are aware of their surroundings in the Light World and remember them in the Dark World, much like Darkners. They can recall events and locations before and when their form is changed through a Dark Fountain, as well as Lightners' interactions with their Light World form. Furthermore, unlike Darkners, plants have heightened senses that extend beyond their immediate vicinity[1]
In Chapter 5, Flowery appears as the main antagonist, with Aqua, Seth, Orange, Yellow, Blue, and Green appearing throughout the chapter. All of them are loyal to Asgore and try to seek his attention, though he shuns it in favor of trying to prove the existence of the Dark World.
After the [I forgot which area but after the great beanstalk], each of the main flowers vow to prevent the party from reaching the Dark Fountain.
After Flowery is defeated by the part, the other flowers can be interacted with, saying their goodbyes before reverting to their Light World forms. Afterwards, Flowery is wounded by the Roaring Knight, and he reverts to his Light World form (cut in half) after giving one last speech to the party.