Cannabis sativa
- Information on Hemp, its physical characteristics, uses and cultivation.
- http://www.ibiblio.org/pfaf/cgi-bin/arr_html?Cannabis+sativa&CAN=LATIND

Plant Profile for Cannabis sativa
- Information from the USDA Plants database.
- http://plants.usda.gov/java/profile?symbol=CASA3

Hemp: A New Crop with New Uses for North America
- By Ernest Small and David Marcus. Reprinted from: Trends in new crops and new uses. 2002. p. 284–326. J. Janick and A. Whipkey (eds.). ASHS Press, Alexandria, VA. One of the best documents about Cannabis on the Web. (PDF file 14.1MB)
- http://www.hort.purdue.edu/newcrop/ncnu02/pdf/small.pdf

Wisconsin Vascular Plants: Species Details
- Cannabis sativa L. hemp, Indian hemp.
- http://www.botany.wisc.edu/wisflora/scripts/detail.asp?SpCode=CANSAT

Flora of North America - Cannabis sativa Linnaeus
- Harvard University Flora Online. Includes description, line drawings, and U.S. distribution map.
- http://flora.huh.harvard.edu:8080/flora/browse.do?flora_id=1&taxon_id=200006342

Ethnobotanical Leaflets - Cannabis: The Hemp Plant
- A publication of Southern Illinois University Herbarium by Ernest G. Walker, Jr. on Cannabis sativa, Cannabis indica, and Cannabis ruderalis. With references.
- http://www.siu.edu/~ebl/leaflets/hemp.htm

Cannabis sativa L.
- Image from Botanical Department - University of Catania.
- http://www.dipbot.unict.it/orto/1037-1.html