Chemical and Morphological Phenotypes in Breeding of Cannabis sativa L. Gianpaolo Grassi and John M. McPartland in S. Chandra et al. (eds.), Cannabis sativa L. - Botany and Biotechnology, Chapter 6, 2017, 137-160. Doi : 10.1007/978-3-319-54564-6_6   Abstract This chapter has two parts. The first part details five characters that contribute to phenotypic diversity in Cannabis. Cannabinoids can be assayed by quantity (dry weight percentage of cannabinoids in harvested material) or by quality (the THC/CBD ratio, or chemotype). Cannabinoid quality is largely genetic, possibly monogenic. We dissect the monogenic inheritance model (two alleles at a single gene locus). Essential oil is composed of volatile, aromatic terpenoids. [...]