This can be purchased over the Internet. It is important to realize that whales, the largest animals, rely on phytoplankton for their survival. Plants are also the basis for agriculture, aquaculture and horticulture. Agriculture is the basis for civilizations large and small. Hunters and gatherers do not develop civilizations.
Plants are immeasurably important in medicine.
Plants provide the air we breathe, the food we eat and they help to conserve and purify the water we drink. They are also beautiful, and beauty is always welcome. Plants also produce wood which is still the most common fuel on the planet. Other uses of wood are manifold. Plant fibers are used used for clothing and paper.