Origin and Habitat: The Opuntia engelmanniiSN|19065]]SN|19920]] has a wide range that extends from Mexico (Aguascalientes, Baja California, Chihuahua, Coahuila, Durango, Guanajuato, Hidalgo, Nuevo Leon, Queretaro, San Luis Potosi, Sinaloa, Sonora, Tlaxcala, Veracruz, Zacatecas) to the United States (Arizona, California, Texas)
Altitude range: 150 to 1,800 metres above sea level.
Habitat and ecology: Desert scrub, dry grasslands, pine-juniper and oak woodland, etc. In the Sonoran Desert, terminal pads face predominantly east-west, so as to maximize the absorption of solar radiation during summer rains. Although found occasionally in the Mojave Desert, it tends to be replaced by Opuntia basilarisSN|19920]]SN|19065]], which does not need the summer rain. Pollinators include solitary bees, such as the Antophoridae, and sap beetles

• Opuntia engelmannii Salm-Dyck ex Engelm.

• Opuntia engelmannii Salm-Dyck ex Engelm.
• Opuntia dillei Griffiths
• Opuntia engelmannii var. alta (Griffiths) Weniger
• Opuntia alta Griffiths
• Opuntia engelmannii var. cacanapa (Griffiths & Hare) Weniger
• Opuntia cacanapa Griffiths & Hare
• Opuntia engelmannii var. cyclodes Engelm. & J.M.Bigelow
• Opuntia cyclodes (Engelm. & J.M.Bigelow) Rose
• Opuntia lindheimeri var. cyclodes (Engelm. & J.M.Bigelow) J.M.Coult.
• Opuntia engelmannii var. discata (Griffiths) C.Z.Nelson
• Opuntia discata Griffiths
• Opuntia phaeacantha var. discata (Griffiths) L.D.Benson & Walk.
• Opuntia engelmannii var. megacarpa (Griffiths) Fosberg
• Opuntia megacarpa Griffiths
• Opuntia occidentalis var. megacarpa (Griffiths) Munz
• Opuntia engelmannii var. subarmata (Griffiths) D.Weniger
• Opuntia lindheimeri var. subarmata (Griffiths) Elizondo & Wehbe
• Opuntia subarmata Griffiths
• Opuntia microcarpa Engelm.
• Opuntia procumbens Engelm. & J.M.Bigelow
• Opuntia tricolor Griffiths

• Opuntia engelmannii subs. aciculata (Griffiths) U.Guzmán & Mandujano
• Opuntia aciculata Griffiths
• Opuntia engelmannii var. aciculata (Griffiths) Weniger
• Opuntia lindheimeri var. aciculata (Griffiths) Bravo
• Opuntia aciculata var. orbiculata Backeb.

• Opuntia engelmannii var. cuija Griffiths
• Opuntia cuija (Griffiths & Hare) Britton & Rose
• Opuntia lindheimeri var. cuija (Griffiths) L.D.Benson
• Opuntia cantabrigiensis Lynch

• Opuntia engelmannii var. dulcis (Engelm.) J.M.Coult. ex K.Schum.
• Opuntia lindheimeri var. dulcis (Engelm.) J.M.Coult.

• Opuntia engelmannii var. flavescens (Peebles) L.D.Benson
• Opuntia flavescens Peebles

• Opuntia engelmannii var. flavispina (L.D.Benson) B.D.Parfitt & Pinkava
• Opuntia phaeacantha var. flavispina L.D.Benson

• Opuntia engelmannii var. flexospina (Griffiths) B.D.Parfitt & Pinkava
• Opuntia flexospina Griffiths
• Opuntia strigil var. flexospina (Griffiths) L.D.Benson

• Opuntia engelmannii subs. lindheimeri (Engelm.) U.Guzmán & Mandujano
• Opuntia engelmannii var. lindheimeri (Engelm.) B.D.Parfitt & Pinkava
• Opuntia lindheimeri Engelm.
• Opuntia tardospina Griffiths
• Opuntia cyanella Griffiths
• Opuntia lindheimeri var. lehmannii L.D.Benson

• Opuntia engelmannii var. linguiformis (Griffiths) B.D.Parfitt & Pinkava
• Opuntia lindheimeri var. linguiformis (Griffiths) L.D.Benson
• Opuntia linguiformis Griffiths

• Opuntia engelmannii subs. lindheimeri cv. Gomei
• Opuntia gomei Griffiths
• Opuntia lindheimeri cv. Gomei Guiggi

Description: Opuntia engelmanniiSN|35254]]SN|19920]] is a very varaible prickly pear, generally forming a dense, mound-shaped shrub, less than 1 metre tall (occasionally tree-like up to 3.5 metres high), usually with no apparent trunk or with a short trunk. Lower branches generally decumbent, upper spreading to ascending.
Remarks: The nomenclatural history of this species is somewhat complicated due to the varieties, as well as its habit of hybridizing with Opuntia phaeacanthaSN|35254]]SN|35254]]. A lot of confusion exists in the identification of this species and Opuntia phaeacanthaSN|19920]]SN|35254]].
Stem segments: Joints obovate to orbicular to rhombic, not disarticulating, flat, glabrous, yellow-green to green (rarely blue-green), obovate to round, or apex tapering, elongate, about 15?30(-120) cm long and 12?20(-40) cm wide, more or less tuberculate.
Areoles: 5-8 per diagonal row across mid-stem segments, evenly distributed on stem segment to absent, subcircular to obovate, 4-7

Bibliography: Major references and further lectures
1) Wikipedia contributors. "Opuntia engelmannii." Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, 20 Jun. 2017. Web. 29 Oct. 2017.
2) Benson 1982 Cacti of US & Can;
3) Hunt & Taylor eds 1990 Bradleya 8:85-107
4) Jepson Manual treatment for "Opuntia engelmannii var. engelmannii" web. Web. 29 Oct. 2017. <http://ucjeps.berkeley.edu/cgi-bin/get_JM_treatment.pl?2702,2726,0,2735>
5) Edward F. Anderson, "The Cactus Family" (Timber Press, 2001), pp.?497-498
6) Raymond M. Turner, Janice E. Bowers, and Tony L. Burgess, "Sonoran Desert Plants: an Ecological Atlas" (Tucson: The University of Arizona Press, 1995) pp.-291-293
7) "Opuntia engelmannii.", "Flora of North America". (FNA Vol. 4 Page 126, 128, 134, 135, 136, 139, 141 ) web: http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=242415194 Retrieved 29 Oct. 2017.
8) Hunt, D., Taylor, N. and Charles, G. (compilers and editors). 2006. "The New Cactus Lexicon." dh Books, Milborne Port, UK.
9) Corral-Diaz, R., Goettsch, B.K., Gomez-Hinostrosa, C., Heil, K., Hernandez, H.M. & Terry, M. 2013. Opuntia engelmannii. The IUCN Red List of Threatened Species 2013: e.T152531A647448. http://dx.doi.org/10.2305/IUCN.UK.2013-1.RLTS.T152531A647448.en. Downloaded on 29 October 2017.

Cultivation and Propagation: Opuntia engelmanniiSN|19920]]SN|19920]] is cultivated as an ornamental plant, for use in drought tolerant gardens, container plantings, and natural landscaping projects. The fruits were a reliable summer food for Native American tribes.