Galeopsis bifida
- Description of Small Hemp-nettle and a photograph.
- http://www.plant-identification.co.uk/skye/labiatae/galeopsis-bifida.htm

Galeopsis tetrahit
- Several photographs of Common Hemp-nettle and some identifying features.
- http://www.plant-identification.co.uk/skye/labiatae/galeopsis-tetrahit.htm

Galeopsis speciosa
- Description of Large-flowered Hemp-nettle and two photographs.
- http://www.plant-identification.co.uk/skye/labiatae/galeopsis-speciosa.htm

Species factsheet for Galeopsis pyrenaica
- Biological Diversity, Biodiversity, Clearing-House Mechanism, CHM
- http://eunis.eea.europa.eu/species-factsheet.jsp?idSpecies=175130&idSpeciesLink=175130&expand=true

Galeopsis ladanum
- photo
- http://crdp.ac-besancon.fr/ressourc/flore/flore/Lamiaceae/photos/galeopsis_ladanum_20.jpg

Galeopsis segetum
- photos
- http://www.kulak.ac.be/facult/wet/biologie/pb/kulakbiocampus/buiten-kulak/lage_planten/Galeopsis%20segetum%20-%20Bleekgele%20hennepnetel/bleekgele%20hennepnetel.htm

Photo/image of Large Hemp-Nettle (Galeopsis speciosa)
- BioPix: Photo of Galeopsis speciosa (Hamp-hanekro).
- http://www.biopix.dk/Photo.asp?PhotoId=1905&Text=1

Hemp-nettle (Galeopsis tetrahit)
- Photo and description of Galeopsis tetrahit
- http://www.ct-botanical-society.org/galleries/galeopsistetr.html

Red Hemp-Nettle
- Photos and description of Galeopsis angustifolia, commonly known as red hemp-nettle
- http://www.arkive.org/species/ARK/plants_and_algae/Galeopsis_angustifolia/