CAMPBELL has written a simple and highly interesting outline of plant geography which can be ... He reviews in a light and pleasant manner the types of vegetation to be found in the north ...

Individual plants produce varying effects, even among the same type of cannabis. It all depends on the plant’s chemical composition and the growing technique used. Cannabis plants contain dozens ...

Nitrogen is a critical limiting element for plant growth and production. It is a major component of chlorophyll, the most important pigment needed for photosynthesis, as well as amino acids ...