5.5 Conclusion
Study of morphological features of plants is crucial for species identification. The
utilization of anatomical and microscopic characters of plants has become a stan-
dard practice especially in plants that exhibit variable morphological features.
Cannabis sativais one such highly complex taxa, exhibiting a wide range of
variations in its morphological features such as habit and size of plants, size and
arrangement of leaves and the shape, size and number of lobes, indumentums, size
and branching of stems, and number and arrangement offlowers. This is possibly
due to the long history of domestication, extensive hybridization, and excessive
selection of preferred phenotypes and chemotypes. Thus, the taxonomy of
Cannabisis confusing. The original geographical distribution of the taxon is vague,
and no purely wild populations exist. As a result, the genus has been treated in
different ways by different authors. Several botanists have proposed thatCannabis
is a polyspecific genus including three different species. Whereas, many others have
opined that it is a monospecific genus with a single species,C. sativa. Some authors
have recognized different varieties and subspecies within the speciesC. sativa.
Several authors have studied the morphology of the species; however, most of them
have focused on the trichome characteristics and their usage in forensic identifi-
cation of the plant material. Further studies of detailed comparative morphological
and anatomical characteristics of the taxon involving a wide range of plant materials
from various parts of its presumed original distribution could yield better under-
standing of the taxonomy of the species as well as the extent of its morphological
and anatomical variations.
Acknowledgements This work was supported in part by the National Institute on Drug Abuse,
National Institute of Health, Department of Health and Human Services, Contract
No. N01DA-10-7773.
References
Anderson LC (1974) A study of systematic wood anatomy inCannabis. Botanical Museum
Leaflets, Harvard University 24:29– 36
Bouquet RJ (1950) Cannabis. Bull Narc 2:14– 30
Briosi G, Tognini F (1894) Intorno alla anatomia della canapa (Cannabis sativaL.). Atti Ist Bot
Pavia 3:91– 209
Dayanandan P, Kaufman PB (1976) Trichomes of Cannabis sativa L. (Cannabaceae). Am J Bot
63:578– 591
Evert RF (2006) Esau’s plant anatomy: meristems, cells, and tissues of the plant body: their
structure, function, and development. John Wiley, Hoboken, New Jersey
Gilmore S, Peakall R, Robertson J (2003) Short tandem repeat (STR) DNA markers are
hypervariable and informative inCannabis sativa: implications for forensic investigations.
Forensic Sci Int 131:65– 74
Hammond CT, Mahlberg PG (1973) Morphology of glandular hairs ofCannabis sativafrom
scanning electron microscopy. Am J Bot 60:524– 528
5 Morpho-Anatomy of Marijuana (Cannabis sativaL.) 135