Origin and Habitat: South-western USA (Texas ), north-western Mexico.
Habitat & Ecology: It grows in dry hills mainly on stony outcrops, often in small colonies usually to the exclusion of other plants.

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

• 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 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 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 engelmannii subs. aciculataSN|19915]]SN|19915]] is a flattened-padded succulent, forming large, hemispherical, bushy clumps up to 60-90 (or more tall) cm tall and 100-300 cm wide. The lower branches decumbent and sending up erect branches.
Stem: Segments obovate or partly rounded at apex, faded and glaucous, dull grey-green more or less glaucous. They measure 10-20 cm. in length.
Leaves: Acicular, awl-shapedup to 7 mm long, ephemeral.
Areoles: Large, widely separated, round. Often spineless.
Glochids: Numerous, 3-12 mm long, acicular, slender, spreading, forming a dense cluster, golden yellow to dark red, thin, long, from all part of the areoles, persisting for several years.
Spines: 1-3 , often absent, reflexed, of a yellowish/toasted colour with a brownish base, up to 3(-5,5) cm in length. Often folded and seemingly decidous.
Flower: Golden yellow, diameter 8-10 cm. Several sources report the flowers as being 'yellow'. But the plant in cultivation usually has bright red-orange flowers, and sometimes the centre is greenish. Petals broad rounded or retuse, filaments yellowish. Stigma dull yellowish with 8-10 green lobes.
Blooming season: Early summer.
Fruit: Pear-shaped, covered with fine spines and glochids, purple.

Bibliography: Major references and further lectures
1) Anderson, E. F. “The cactus family” 2001.
2) Hunt, D., Taylor, N. and Charles, G. “The New Cactus Lexicon.” dh Books, Milborne Port, UK. 2006
3) N. L. Britton, J. N. Rose: “The Cactaceae. Descriptions and Illustrations of Plants of the Cactus Family.” Vol I, The Carnegie Institution of Washington, Washington 1919
4) Joseph Nelson Rose “Studies of Mexican and Central American Plants” Volume 1, U.S. Government Printing Office, 1909

Cultivation and Propagation: It is a low maintenance plant that tolerate considerable neglect and will naturalize, it is drought-tolerant; and suitable for xeriscaping. Easy to cultivate outdoor in dry, sandy or gravely, well-drained soils. May be grown in clay soils as long as drainage is good and soils do not remain wet, it is very adaptable both in acid, neutral and basic (alkaline) soils, but prefers a pH in the range 6 to 7.5. No serious insect or disease problems.
Watering Needs: Outdoors little or no water once established, in the green house irrigate regularly from March to october, keep fairly dry in winter, tolerate dry condition but suffer if exposed to prolonged and severe drought. A position at the base of a south-facing wall or somewhere that can be protected from winter rain is best for this plant, but is however resistant to moisture and rain.
Sun Exposure: Full sun (only), in semi shaded position wont produce many flowers.
Frost hardiness: They are reasonably cold hardy , tolerating temperatures down to -5° to -12° C (USDA: 8-10) depending on clone, they are also quite tolerant of winter wet. (In good drained soils)
Traditional uses: The fruit are edible and the tender joints can be coked as a vegetable. In medicine the plant are used to treat dyspepsia, mumps, swelling and in veterinary it is used to treat bruises. The joints are also a good food for cattle (after burning of spines)
Propagation: Propagated by cuttings of leaf pads at any time in the growing season. (Allow cut surface to callus over before planting).