As used in this chapter, the following terms shall have the meanings indicated:
All grass, plant life or vegetation whatsoever, which is not edible or is not planted for some useful or ornamental purpose or which throws off any unpleasant or noxious odor, which conceals any filthy deposits, or tends to create or produce pollen. This term shall not include trees, hedges, shrubs, Canada thistles, Cichorium intybus (commonly known as "chickory" or "succory" or "blue daisy"), or marijuana.