Echinocereus websterianus
- Photographs and information on this species.
- http://www.desert-tropicals.com/Plants/Cactaceae/Echinocereus_websteri.html

Echinocereus subinermis
- Photographs and information on this species.
- http://www.desert-tropicals.com/Plants/Cactaceae/Echinocereus_subinermis.html

Echinocereus triglochidiatus
- Photographs and description of the Hedgehog or Claret Cup Cactus and information on its habitat and range.
- http://www.desertusa.com/mag00/mar/papr/hhog.html

Echinocereus stoloniferus ssp. tayopensis
- Photographs and information on this species.
- http://www.desert-tropicals.com/Plants/Cactaceae/Echinocereus_tayopensis.html

Echinocereus Online
- An electronic magazine about the genus, in German and English. Includes many images.
- http://www.echinocereus.de/

Echinocereus pentalophus
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- http://florawww.eeb.uconn.edu/acc_num/198502000.html

Echinocereus blankii
- image
- http://www.dipbot.unict.it/orto/0959-1.html