Origin and Habitat: Echinocereus mombergianus is endemic to the Sierra San Pedro Martir, in the Mexican state of Baja California Norte.
Type locality: Hidalgo Observatory, Baja California, Mexico, 1900-2800 metres above sea level.
Habitat and Ecology: This species occurs in temperate forest in the Sierra de San Pedro Martir (Parque National Sierra San Pedro Martir). In very sunny locations (it grow in the crevices of granite at the edge of a pine forest) spines are especially thick and strong. Nothing is known about the population size or trends. There is no information on the threats for this species.

• Echinocereus mombergerianus G.Frank
• Echinocereus pacificus subs. mombergerianus (G.Frank) W.Blum, W.Rischer & Rutow in W.Blum et al.
• Echinocereus polyacanthus subs. mombergerianus (G.Frank) Breckw.

• Echinocereus polyacanthus Engelm. in Wisliz.
• Echinocereus triglochidiatus subs. polyacanthus (Engelm.) U.Guzmán
• Echinocereus triglochidiatus var. polyacanthus (Engelm.) L.D.Benson
• Echinocereus leeanus (Hook.) Lem.
• Cereus leeanus Hook.
• Echinocereus leanus
• Echinocereus matthesianus Backeb.
• Echinocereus multicostatus (Cels) Cels ex Rümpler
• Cereus multicostatus Cels
• Echinocereus leanus var. multicostatus (Cels) K.Schum.
• Echinocereus triglochidiatus var. multicostatus (Cels) W.T.Marshall
• Echinocereus santaritensis W.Blum & Rutow in W.Blum et al.

• Echinocereus polyacanthus subs. acifer (Otto ex Salm-Dyck) N.P.Taylor
• Cereus acifer Otto ex Salm-Dyck
• Echinocereus acifer (Otto ex Salm-Dyck) F.Haage
• Echinocereus triglochidiatus var. acifer (Salm-Dyck) Bravo
• Echinocereus acifer subs. tubiflorus W.Rischer in W.Blum et al.
• Echinocereus marksianus Fritz Schwarz in Backeb.
• Echinocereus polyacanthus var. densus (Regel) N.P.Taylor
• Echinocereus polyacanthus var. densa ( Regel ) N.P.Taylor (Regel) N.P.Taylor
• Echinopsis valida var. densa Regel

• Echinocereus polyacanthus subs. huitcholensis (F.A.C.Weber) N.P.Taylor
• Cereus huitcholensis F.A.C.Weber
• Echinocereus acifer subs. huitcholensis (F.A.C.Weber) Mich.Lange
• Echinocereus huitcholensis (F.A.C.Weber) Gürke
• Echinocereus polyacanthus var. huitcholensis (F.A.C.Weber) N.P.Taylor
• Echinocereus triglochidiatus subs. huitcholensis (F.A.C.Weber) U.Guzmán
• Echinocereus plomosus hort.

• Echinocereus polyacanthus subs. pacificus (Engelm. ex Orcutt) Breckw.
• Cereus pacificus (Engelm.) J.M.Coult.
• Cereus phoeniceus var. pacificus Engelm. ex Orcutt
• Echinocereus pacificus (Engelm. ex Orcutt) Britton & Rose
• Echinocereus polyacanthus var. pacificus (Engelm. ex Orcutt) N.P.Taylor
• Echinocereus triglochidiatus subs. pacificus (Engelm. ex Orcutt) U.Guzmán
• Echinocereus triglochidiatus var. pacificus (Engelm. ex Orcutt) Bravo
• Echinocereus triglochidiatus var. pacificus (Engelm. ex Orcutt) W.T.Marshall
• Echinocereus mombergerianus G.Frank
• Echinocereus pacificus subs. mombergerianus (G.Frank) W.Blum, W.Rischer & Rutow in W.Blum et al.
• Echinocereus polyacanthus subs. mombergerianus (G.Frank) Breckw.

Description: Echinocereus mombergerianusSN|10576]]SN|7114]] is a caespitose cactus forming large cushions up to 70 cm in diameter, generally with 30-100 (150) individual shoots, branching from the base or side. The dull green stems are covered by yellow-brown spines and showy red flowers are freely produced in spring. The taxonomy of Echinocereus mombergerianusSN|7070]]SN|7114]] is controversial, it is not certain if it is a local or morphological form of the very variable Echinocereus polyacanthusSN|7070]]SN|7070]] or of Echinocereus polyacanthusSN|7114]]SN|7070]] subs. pacificus, moreover some traits (The thick, fleshy petals, the floral-tube almost devoid of wool) get this species close to Echinocereus triglochidiatusSN|7114]]SN|10576]].
Stem: Cylindrical, mostly erect, 15-28 cm long, 3-5 (6) cm across light yellow-green to dull green.
Ribs: (10-)11-12 (-13) slightly tuberculate, 8-12 mm apart.
Areoles: Round, 3-5 mm in diameter, with a light beige to grey felt, about 10 mm apart.
Roots: Fibrous.
Central spines: 3-4, 30-80 mm long (in sunny locations occasionally up to 100 mm long), 0.3-0.7 mm in thick at the base, often somewhat angular, twisted and pointed, straight or up curved and spreading, longer ones pointing sidewards or slightly downwards, the new growth yellow to yellow-brown, sometimes brown, later horn coloured with yellow-brown tips.
Radial spines: 8-12, 5-20 mm long, (0.2 mm maximum thickness), spreading, located mainly on the sides, straight, but also curved, light horn coloured with yellow tips.
Flowers: Funnel-shaped, 4-5 cm long, 2.5-4 cm in diameter. Tepals 15 mm long and 3-4 mm wide, lanceolate, thick, fleshy, rusty-red to the orange-yellow, the receptacle with a slight green tint. Filaments yellow, sometimes light grey-violet. Anthers light grey-purple to grey magenta. Pollen straw-yellow. Style yellowish-white. Stigma lobes c. 9 , yellow-green. Flower tube 2.5-3.5 cm long and 6-8 mm in diameter, apple-green, smooth, with small round areoles, which bear little white wool and 8-9 spines mainly directed upward with brown tips. Each areola is subtended by a small fleshy scale. The flowers indeed are quite variable, sometime they are smaller or with two whorls of petals, or with filaments and anthers grey-magenta.
Fruit: Small, oval (12 x 20 mm) with flower remnants (15-20 mm long) at first brown-green, then purple-red, later turning brown with round areoles about 1 mm in diameter with 8-12 thin white spines 6-10 mm long with brown tips, and a few very short curly white hair.
Seeds: About 1.6 mm long and about 1.2 mm wide, black, shiny, divided into very low warts with weak cuticular folding limited to the edge zone.

Bibliography: Major references and further lectures
1) León de la Luz, J.L., Gómez-Hinostrosa, C. & Hernández, H.M. 2013. Echinocereus mombergerianus. The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 01 May 2015.
2) Frank G.R.W. (1989) "Echinocereus mombergerianus spec.nov. G.R.W. Frank - Eine sehr interessante Art aus der Sierra San Pedro Martir in Baja California del Norte." Kakt. u.a. Sukk. 40 (11): 272–277.
3) Frank G.R.W. (1990) "Nachtrag zur Erstbeschreibung von Echinocereus mombergerianus G.R.W. FRANK." Kakt. u.a. Sukk. 41 (11): 261.
4) Lau, A.B. (1983): “Field Numbers of Dr Alfred B.Lau - Mexico and South America.” Joshi Marg, Bombay, India
5) Taylor, N.P. (1985): “The Genus Echinocereus”, A Kew Magazine Monograph: 64. Collingridge Books
6) Frank, G.R.W. (1986): “Die Echinocereen von Baja California” - Kakt. and. Sukk. 37 (5): 90-98
7) Momberger, P. (1988): “Erkenntnisse zur Echinocereenflora der Baja California” - KaktusbHite: 28-31. Verein der Kakteenfreunde Kainz/Wiesbaden
8) Blum. W. (1989): “Auf dem Weg zum Standort Е. spec. Lau 1248”. - Der Echinocereenfreund (2): 41-44. Arbeitsgruppe Echinocereen der DUG
9) Taschenlexikon der Farben, Musterschmidt-Verlag, Zurich-Gottingen, 1975 (2. Auflage).

Cultivation and Propagation: This cactus is widely cultivated for its flowers. It is among the easiest species to grow, flower and propagate. Water regularly from March to October. Rot prone in winter, it needs good drainage. Claret Cups require strong sunlight to maintain a healthy appearance, and a harsh "dry and cool" winter environment combined with maximum light exposure enhances spring flower production.
Frost Tolerance: Depends on the variety. The species from Baja California is less resistant (hardy to -5° C); the other varieties are much more cold resistant (some populations can tolerate temperatures down to -12° C or less)