Origin and Habitat: Coahuila, Nuevo León, Tamaulipas, San Luis Potosi, and Zacatecas
Habitat: It is a widespread and common species in the southern Chihuahuan Desert, at elevations of 1450 to 1900 metres above sea level. It occurs mainly on the top of limestone hills in xerophytic shrubland together with Mammillaria rubrograndisSN|5392]]SN|26070]] and Mammillaria glassiiSN|26070]]SN|5392]] var. nominis-dulcis|SN|5398]].

• Echinocereus parkeri N.P.Taylor

• Echinocereus parkeri subs. arteagensis W.Blum & Mich.Lange in W.Blum et al.
• Echinocereus parkeri f. arteagensis (W.Blum & Mich.Lange) G.Frank & E.Scherer

• Echinocereus parkeri subs. gonzalezii (N.P.Taylor) N.P.Taylor
• Echinocereus parkeri var. gonzalezii N.P.Taylor

• Echinocereus parkeri subs. mazapilensis W.Blum & Mich.Lange in W.Blum et al.
• Echinocereus parkeri var. mazapilensis K.Neumann

Description: Echinocereus parkeriSN|21819]]SN|15573]] is one of the smaller clumping Echinocerei, forming low bushes. It is generally uncommon species in collections, easy to grow and ready flowering. Has tapered stems protected by 5 cm long straight spines.
Related species: Echinocereus parkeriSN|10577]]SN|15573]] has points in common with Echinocereus viereckiiSN|7817]]SN|21819]], Echinocereus stramineusSN|21819]]SN|7817]] and Echinocereus nivosusSN|15573]]SN|10577]]. It is between them in both taxonomic and geographic senses, and leaves no room for doubt that they and their other allies forms a natural species complex. Charlie Glass thought it was closely related to Echinocereus viereckiiSN|15573]]SN|21819]], possibly conspecific.
Habit: Plants with many stems, forming compact mounds or open clumps.
Stems: Tapering or cylindrical, to 15 cm high, 2-6 cm in diameter.
Ribs: 6-10, deeply tuberculate.
Central spines: 1-8, dark, becoming glassy white to yellowish, 2-6,5 cm long.
Radial spines: 6-18, usually glassy white, very slender, 7-12 mm long.
Flowers: Almost apical,diurnal, very showy, 4,5-5,5 cm long, 4,5-6 cm in diameter, funnel-form, magenta to deep pink, with white throats.
Fruits: Almost spherical, green with white pulp, with glassy white spines tending to fall off.

Bibliography: Major references and further lectures
1) Edward Anderson “The Cactus family” Timber Press, Incorporated, 2001
2) Nathaniel Lord Britton, Joseph Nelson Rose “Cactaceae: Descriptions and Illustrations of Plants of the Cactus Family” vol. 4 The Carnegie Institution of Washington, Washington 1923
3) James Cullen, Sabina G. Knees, H. Suzanne Cubey "The European Garden Flora Flowering Plants: A Manual for the Identification of Plants Cultivated in Europe, Both Out-of-Doors and Under Glass" Cambridge University Press, 11/Aug/2011
4) David R Hunt; Nigel P Taylor; Graham Charles; International Cactaceae Systematics Group. "The New Cactus Lexicon" dh books, 2006
5) N. P. Taylor: “Supplementary notes on Mexican Echinocereus Echinocereus parkeri” in "Bradleya: Yearbook of the British Cactus and Succulent Society", The Society, volume 6, pages 73–74. 1988.
6) Fitz Maurice, B, Fitz Maurice, W.A., Hernández, H.M. & Sotomayor, M. 2013. Echinocereus parkeri. In: IUCN 2013. "IUCN Red List of Threatened Species." Version 2013.1. <www.iucnredlist.org>. Downloaded on 22 October 2013.

Cultivation and Propagation: Echinocereus parkeriSN|15573]]SN|15573]] is a summer-growing species of relatively easy cultivation. It is adapted to dry soils and is quite susceptible to over-watering if kept in a non ventilated place.
Growth rate: Slow-growing.
Soil: Grow it in an open mineral, sandy-gritty cactus compost and provide a very good drainage.
Exposure: It is suited for sunny-brightly exposure, but can tolerate light shade. However it will do its best only with lots of sun and become stressed with inadequate light which could result in poor growth and unnatural shape. It has a good heat tolerance.
Watering: Water sparingly and keep it completely dry during winter. Mature individuals easily rot and die especially after transplanting so be extremely cautious with watering. Keep dry in winter or when night temperatures remain below 10° C. Water it less than average if in bigger pots.
Fertilization: Feed them once during the growing season with a fertilizer specifically formulated for cactus and succulents (high potash fertilizer with a dilute low nitrogen), including all micro nutrients and trace elements diluted to ½ the strength recommended on the label. They thrive in poor soils and need a limited supplies of fertilizer to avoid the plants developing excess vegetation, which is easily attacked by fungal diseases.
Special need: It is suited for airy exposures. Provide very good ventilation. Nearly all problems occur as a result of overwatering and poor ventilation, especially when weather conditions are dull and cool or very humid. They must have very dry atmosphere.
Hardiness: It likes warmth (recommended minimum winter temperature 5° C) But plants kept perfectly dry can easily survive to frequent moderate frost, above approx -7° C.
Pests & diseases: These cacti may be attractive to a variety of insects, but plants in good condition should be nearly pest-free, particularly if they are grown in a mineral potting-mix, with good exposure and ventilation. Nonetheless, there are several pests to watch for:
- Red spiders: Red spiders may be effectively rubbed up by misting the plants from above.
- Mealy bugs: Mealy bugs occasionally develop aerial into the new leaves and flowers with disfiguring results, but the worst types develop underground on the roots and are invisible except by their effects.
- Scales, thrips and aphids: These insects are rarely a problem.
- Rot: Rot is only a minor problem if the plants are watered and “aired” correctly. If they are not, fungicides won't help all that much.
Propagation: Seed or cuttings. The seeds can be sown in pots of fine, well-drained sandy soil, any time during the spring when temperatures are warm. Cover the seeds with a fine layer of grit and water from below with a fungicide to prevent damping off. For the 1-2 weeks cover the pots with a sheet of glass/clear perspex to keep the humidity levels high. Remove the glass and replace it with light shade-cloth and mist once or twice a day for the next two weeks after which most seeds should have germinated. From then on mistings can be reduced to every second and then every third day as the little plants grow. The seedlings should not be disturbed until they are well rooted after which they can be planted separately in small pots. Sometimes it is grafted to avoid root rot problems as plants grafted on an hardy stock are easy to grow and no special skill is required.