Pepper (Piper nigrum L.)
- Detailed description of black pepper and its uses, with images.
- http://www.uni-graz.at/~katzer/engl/generic_frame.html?Pipe_nig.html

Lycaeum - Leda - Piper
- Photos, brief information, and links related to the use of over 20 species.
- http://leda.lycaeum.org/?ID=427

Piper betel
- Short description and medicinal uses of the betel plant, a climbing shrub which is indigenous throughout the Indian Malay region and is cultivated in other tropical regions.
- http://www.botanical.com/botanical/mgmh/b/bethel33.html

Piper geniculatum
- Photograph of the plant.
- http://www.dipbot.unict.it/orto/0702-1.html

Piper nigrum
- Image of leaf margin and fruit.
- http://www.botany.hawaii.edu/faculty/carr/images/pip_nig_fr.jpg