Echinocereus is a genus of ribbed, usually small to medium-sized, cylindrical shaped cacti, comprising about 70 species native to the southern United States and Mexico in very sunny, rocky places. Usually the flowers are large and the fruit edible.
The name comes from the Ancient Greek ἐχῖνος (echinos), meaning "sea urchin", and the Latin cereus meaning "candle". They are sometimes known as hedgehog cacti, a term also used for the Pediocactus and Echinopsis.
Description The species of the genus Echinocereus grow solitary or branching with prostrate to erect shoots that are spherical to cylindrical. The roots are fibrous or bulbous. The plants reach heights of growth between 1 and 60 centimeters. On the tips of the 4 to 26 ribs, which are mostly clear and only rarely resolved into humps, are the areoles, from which differently shaped spines can arise.
A distinctive characteristic and likely synapomorphy of the genus is the erumpent flowers.Sánchez, D., Grego-Valencia, D., Terrazas, T., & Arias, S. (2015). How and why does the areole meristem move in Echinocereus (Cactaceae)?. Annals of Botany, 115(1), 19-26. The floral buds develop internally and break through the epidermis of the stem. This flower morphology is likely an adaptation to protect the developing buds from low temperatures. Upon maturity, the flowers are usually brightly colored and open during the day. Echinocereus floral color is variable because perianth color reflects pollinator specificity. Red flowers are generally associated with hummingbird pollination, while pink flowers tend to correspond to moth pollination. Their pericarp and floral tubes are studded with thorns, bristles, and sometimes wool. The scar is usually green, but sometimes white in color.
The spherical to ovoid fruits are green to red and mostly thorny. They are mostly juicy and open along a longitudinal slit. The sometimes fragrant fruits contain broadly oval, black, tuberous seeds 0.8 to 2 millimeters long.
Taxonomy Echinocereus is a genus in the tribe Echinocereeae within the subfamily Cactoideae of the Cactaceae family.United States Department of Agriculture. Germplasm Resources Information Network - (GRIN) [Online Database]. National Germplasm Resources Laboratory, Beltsville, Maryland. URL: http://www.ars-grin.gov/cgi-bin/npgs/html/genus.pl?4097 (11 October 2012). The Cactoideae can be further divided into two sister clades, Cactoideae I and II.Hernández‐Hernández, T., Hernández, H. M., De‐Nova, J. A., Puente, R., Eguiarte, L. E., & Magallón, S. (2011). Phylogenetic relationships and evolution of growth form in Cactaceae (Caryophyllales, Eudicotyledoneae). American journal of botany, 98(1), 44-61. Echinocereus is situated within the Cactoideae I clade within the Pachycereeae tribe, a tribe that represents a diversification that yielded columnar and arborescent forms. Echinocereus emerged 4.6 ± 1.7 million years ago.Arakaki, M., Christin, P. A., Nyffeler, R., Lendel, A., Eggli, U., Ogburn, R. M., ... & Edwards, E. J. (2011). Contemporaneous and recent radiations of the world's major succulent plant lineages. Proceedings of the National Academy of Sciences, 108(20), 8379-8384. Echinocereus is a strongly supported monophyletic genus that is sister to Stenocereus, although there has historically been substantial debate about infrageneric classification because of the genus's high rates of morphological variation and convergent evolution.
Cultivation Echinocereus spp. are easier to cultivate than many other cacti. They need light soil, a sunny exposure, and a fresh and dry winter to flower. They grow better in soil slightly richer than other cacti. In the wild, several of the species are cold hardy, tolerating temperatures as low as −23 °C, but only in dry conditions.
Species The following species are recognized in the genus Echinocereus by Plants of the World Online. They are separated by sections established in Phylogeny in Echinocereus (Cactaceae) based on combined morphological and molecular evidence: taxonomic implications 2017. Section Image Scientific name Subspecies Distribution Costati Echinocereus berlandieri Mexico, Texas Echinocereus cinerascens Echinocereus cinerascens subsp. cinerascens Echinocereus cinerascens subsp. septentrionalis Echinocereus cinerascens subsp. tulensis Texas to Mexico Echinocereus enneacanthus Mexico (Jalisco) Echinocereus freudenbergeri Mexico (S. Coahuila) Echinocereus longisetus Echinocereus longisetus subsp. delaetii Echinocereus longisetus subsp. longisetus Mexico (Coahuila). Echinocereus nivosus Mexico (SE. Coahuila, Nuevo León) Echinocereus papillosus Texas to NE. Mexico Echinocereus parkeri Echinocereus parkeri subsp. arteagensis Echinocereus parkeri subsp. gonzalezii Echinocereus parkeri subsp. mazapilensis Echinocereus parkeri subsp. parkeriMexico. Echinocereus rayonesensis Mexico (Coahuila, Nuevo León, Tamaulipas). Echinocereus stramineus New Mexico to W. Texas and NE. Mexico Echinocereus viereckii Echinocereus viereckii subsp. morricalii Echinocereus viereckii subsp. viereckii Mexico (SW. Tamaulipas, Nuevo León, Coahuila). Echinocereus zapalinamensis Mexico (Coahuila) Echinocereus Echinocereus blumii Mexico (Coahuila) Echinocereus canus Texas Echinocereus carmenensis W.Blum, Mich.Lange & SchererMexico (Coahuila) Echinocereus chloranthus SE. Arizona to W. Texas and Mexico (Chihuahua) Echinocereus davisii Texas Echinocereus mapimiensis Mexico (Coahuila, Durango) Echinocereus milleri Texas Echinocereus neocapillus W. Texas Echinocereus pentalophus Echinocereus pentalophus subsp. leonensis Echinocereus pentalophus subsp. pentalophus Echinocereus pentalophus subsp. procumbens Texas, Mexico (to Jalisco) Echinocereus occidentalis Echinocereus occidentalis subsp. breckwoldtiorum Echinocereus occidentalis subsp. occidentalisMexico Echinocereus russanthus Texas to Mexico (Chihuahua, Coahuila) Echinocereus viridiflorus Echinocereus viridiflorus subsp. correllii Echinocereus viridiflorus subsp. viridiflorusSW. South Dakota to N. Texas and Mexico (Coahuila)Erecti Echinocereus apachensis Arizona. Echinocereus barthelowianus Mexico (Island Magdalena) Echinocereus bonkerae Arizona Echinocereus brandegeei Mexico (Baja California) Echinocereus dasyacanthus Echinocereus dasyacanthus subsp. ctenoides Echinocereus dasyacanthus subsp. dasyacanthus Echinocereus dasyacanthus subsp. multispinosus Echinocereus dasyacanthus subsp. rectispinus Mexico (Coahuila) Echinocereus engelmannii Echinocereus engelmannii subsp. engelmannii Echinocereus engelmannii subsp. llanuraensis United States (Arizona, Colorado, New Mexico, Texas, Utah), Mexico Echinocereus fasciculatus Colorado to NE. Mexico. Echinocereus felixianus New Mexico, Texas, Mexico (N. Sonora to N. Chihuahua) Echinocereus fendleri Echinocereus fendleri subsp. fendleri Echinocereus fendleri subsp. rectispinus Arizona, California, Nevada, Utah; Mexico (Baja California, NW. Sonora). Echinocereus ferreirianus Echinocereus ferreirianus subsp. ferreirianus Echinocereus ferreirianus subsp. lindsayorum Mexico (C Baja California) Echinocereus ledingii Arizona.Echinocereus llanurensis (Rutow) W.Blum & D.FelixMexico (NW Sonora) Echinocereus maritimus Mexico (Baja California) Echinocereus nicholii Arizona to Mexico (Sonora) Echinocereus pectinatus Echinocereus pectinatus subsp. pectinatus Echinocereus pectinatus subsp. rutowiorum Echinocereus pectinatus subsp. wenigeri Mexico. Echinocereus perplexus Texas Echinocereus relictus UtahPulchellus Echinocereus acanthosetus Mexico Echinocereus adustus Echinocereus adustus subsp. adustus Echinocereus adustus subsp. roemerianus Echinocereus adustus subsp. schwarzii Mexico (Chihuahua) Echinocereus knippelianus Mexico (SE. Coahuila, Nuevo León, Tamaulipas, San Luis Potosí). Echinocereus laui Mexico (E. Sonora, Chihuahua) Echinocereus pamanesii Echinocereus pamanesii subsp. bonatzii Echinocereus pamanesii subsp. pamanesiiMexico (Zacatecas) Echinocereus pulchellus Mexico (Hidalgo, Puebla) Echinocereus schereri Mexico (Durango). Echinocereus sharpii Mexico (Nuevo León) Echinocereus weinbergii Echinocereus weinbergii subsp. venustus Echinocereus weinbergii subsp. weinbergiiMexico (Jalisco)Reichenbachii Echinocereus bristolii Mexico (Sonora) Echinocereus chisosensis Echinocereus chisosensis subsp. chisosensis Echinocereus chisosensis subsp. fobeanus Texas to Mexico Echinocereus grandis Mexico (Islands de las Animas) Echinocereus palmeri Echinocereus palmeri subsp. mazapil Echinocereus palmeri subsp. palmeriMexico (Chihuahua, Durango) Echinocereus primolanatus Mexico (to Jalisco). Echinocereus pseudopectinatus Arizona to Mexico (NE. Sonora) Echinocereus reichenbachii Echinocereus reichenbachii subsp. armatus Echinocereus reichenbachii subsp. baileyi Echinocereus reichenbachii subsp. burrensis Echinocereus reichenbachii subsp. fitchii Echinocereus reichenbachii subsp. perbellus Echinocereus reichenbachii subsp. reichenbachiiColorado, Kansas, New Mexico, Oklahoma, Texas; Mexico Echinocereus rigidissimus Echinocereus rigidissimus subsp. rigidissimus Echinocereus rigidissimus subsp. rubispinus New Mexico, Arizona and N. Mexico Echinocereus sciurus Echinocereus sciurus subsp. floresii Echinocereus sciurus subsp. sciurusMexico (S Baja California Sur) Echinocereus scopulorum Mexico (to Nayarit) Echinocereus spinigemmatus Mexico (NW Jalisco, W Zacatecas) Echinocereus stoloniferus Echinocereus stoloniferus subsp. stoloniferus Echinocereus stoloniferus subsp. tayopensis Mexico (SE Sonora, Sinaloa) Echinocereus subinermis Echinocereus subinermis subsp. ochoterenae Echinocereus subinermis subsp. subinermisMexico (Sonora, Sinaloa, SW Chihuahua, Durango) Echinocereus websterianus Mexico (Sonora: Island San Pedro Nolasco) Triglochidiata Echinocereus acifer Mexico Echinocereus arizonicus Echinocereus arizonicus subsp. arizonicus Echinocereus arizonicus subsp. matudae Echinocereus arizonicus subsp. nigrihorridispinus Arizona, New Mexico, Mexico Echinocereus bakeri Arizona, Nevada, Utah Echinocereus coccineus Echinocereus coccineus subsp. coccineus Echinocereus coccineus subsp. paucispinus Echinocereus coccineus subsp. rosei New Mexico and Mexico (Sonora, Sinaloa, Chihuahua) Echinocereus gurneyi Texas. Echinocereus huitcholensis Mexico (SE. Sinaloa to NW. Jalisco) Echinocereus marksianus Mexico (San Luis Potosí) Echinocereus ortegae Echinocereus ortegae subsp. koehresianus Echinocereus ortegae subsp. ortegaeMexico Echinocereus pacificus Echinocereus pacificus subsp. mombergerianus Echinocereus pacificus subsp. pacificusMexico (Baja California) Echinocereus polyacanthus Mexico (Chihuahua to Jalisco). Echinocereus salm-dyckianus Mexico (E. Sonora to W. Chihuahua) Echinocereus santaritensis Echinocereus santaritensis subsp. bacanorensis Echinocereus santaritensis subsp. santaritensisArizona to New Mexico and Mexico (Sonora, Chihuahua) Echinocereus scheeri Echinocereus scheeri subsp. gentryi Echinocereus scheeri subsp. scheeriMexico (E. Sonora to W. Durango) Echinocereus triglochidiatus Echinocereus triglochidiatus subsp. mojavensis Echinocereus triglochidiatus subsp. triglochidiatusColorado to New Mexico and NW. Mexico. Echinocereus yavapaiensis Arizona Wilcoxia Echinocereus kroenleinii Mexico (Coahuila) Echinocereus leucanthus Mexico (NW. Sonora, NW. Sinaloa) Echinocereus poselgeri Texas to NE. Mexico. Echinocereus schmollii Mexico (SE. Querétaro to Hidalgo) Echinocereus waldeisii Mexico (San Luis Potosí)
Natural hybrids Image Scientific name Subspecies Distribution Echinocereus × kunzei ( E. coccineus × E. dasyacanthus.) New Mexico Echinocereus × neomexicanus (E. chloranthus × E. coccineus subsp. rosei. ) Mexico (Chihuahua) Echinocereus × roetteri (E. coccineus × E. dasyacanthus) Echinocereus ×roetteri var. lloydii Echinocereus ×roetteri var. neomexicanus New Mexico to SW. Texas and Mexico (Chihuahua)
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