L. subsp. sativa var. sativa, domesticated variety. C. sativa L. subsp. sativa var. spontanea Vav., wild or escaped variety. C. sativa L. subsp. indica (Lam.) Small & Cronq., primarily selected for drug production. C. sativa L. subsp. indica var. indica, domesticated variety. C. sativa subsp. indica var. kafiristanica (Vav.) Small & Cronq, wild or escaped variety. This classification was based on several factors including interfertility, chromosome uniformity, chemotype, and numerical analysis of phenotypic characters. Professors William Emboden, Loran Anderson, and Harvard botanist Richard E. Schultes and coworkers also conducted taxonomic studies of Cannabis in the 1970s, and concluded that stable morphological differences exist that support recognition of at least three species, C. sativa, C. indica, and C. ruderalis. For Schultes, this was a reversal of his previous interpretation that Cannabis is monotypic, with only a single species.<ref name="schultes1970a">{{cite book | vauthors = Schultes RE | date = 1970 | chapter = Random thoughts and queries on the botany of Cannabis | veditors = Joyce CR, Curry SH | title = The Botany and Chemistry of Cannabis | publisher = J. & A. Churchill | location = London | pages = 11–38 }}</ref> According to Schultes' and Anderson's descriptions, C. sativa is tall and laxly branched with relatively narrow leaflets, C. indica is shorter, conical in shape, and has relatively wide leaflets, and C. ruderalis is short, branchless, and grows wild in Central Asia. This taxonomic interpretation was embraced by Cannabis aficionados who commonly distinguish narrow-leafed "sativa" strains from wide-leafed "indica" strains. McPartland's review finds the Schultes taxonomy inconsistent with prior work (protologs) and partly responsible for the popular usage. Continuing research Molecular analytical techniques developed in the late 20th century are being applied to questions of taxonomic classification. This has resulted in many reclassifications based on evolutionary systematics. Several studies of random amplified polymorphic DNA (RAPD) and other types of genetic markers have been conducted on drug and fiber strains of Cannabis, primarily for plant breeding and forensic purposes. Dutch Cannabis researcher E.P.M. de Meijer and coworkers described some of their RAPD studies as showing an "extremely high" degree of genetic polymorphism between and within populations, suggesting a high degree of potential variation for selection, even in heavily selected hemp cultivars. They also commented that these analyses confirm the continuity of the Cannabis gene pool throughout the studied accessions, and provide further confirmation that the genus consists of a single