Great question!
Plant:
"A place where an industrial or manufacturing process takes place."
Green plants manufacture sugars, starches, proteins, lipids, leaves, fruits, seeds, etc.
They import raw materials like water, mineral salts and CO2.
They have energy requirements (sunlight and warmth).
They sometimes export their seeds by flinging or flying, but usually they rely on subcontractors like birds, squirrels, gardeners and farmers to move and consume their products.
I think they only things they don't have is lobbyists and lawyers.
