Potted plants

Potted plants are items in for sale at Plant Empire.

Background
From "The Mysterious Flashing Red Light" to "Hospital," the plants sat on wooden shelves collecting dust.

In an episode that was really long, but a complete waste of time and added nothing, pretty flower boy bought some potted plants from some creepy old dude that owns a tiny plant shop in the middle of a big city.

In "Carpet Dime", upon seeing Fontaine, Marshall ran downstairs, grabbed the plants off of the table, ran upstairs and threw them at Fontaine. He then yelled "ALCHEM MAN BAD."

In between "Risky Business" and "Lord of the Game," the plants died in the three-month time skip and were never heard from again.

In the epilogues of "Dark Energy," the plants suddenly come back to life, haunt the lab and escape to terrorize Silivia.

Named plants

 * Bartholomew Aragonite - Atticus' basil. Basil is a Mary Sue, the perfect protagonist. He is all about Truth, Justice, and the Euclidean Way.
 * Cecil - Steven's cilantro. He has no defined personality traits and dies without any development whatsoever.
 * Pandora - Melissa's poinsettia. They were originally crying, stuttering, little plants, but suddenly became some power-grabbing bitch.
 * Zahra - Savannah Whitesmith's former plant and Blossom Cane's oregano. Since Savannah died, Marshall gave the oregano to Blossom. They reside in her apartment, where they are ugly and wear black rags.

Role in series
They, by far, have the greatest role in the series as they convert carbon dioxide into much-needed oxygen.