Origin and Habitat: Western Argentina (Jujuy, Salta and Tucumán) and southern Bolivia (Tarija and Chuquisaca).
Type locality: Between Tucuman and Salta, Argentina.
Altitude range: It grows at elevations of 600 to 2,500 metres above sea level.
Habitat and Ecology: This species grows in many habitat types, such as grasslands, shrublands, and forests. This species is locally but has a patchy distribution. Field observations indicate that the populations are steadily declining due to expanding agriculture, urbanization and extraction for ornamental use.

• Echinopsis ancistrophora Speg.
• Cereus pasacanus (F.A.C.Weber ex Rümpler) F.A.C.Weber
• Mesechinopsis ancistrophora (Speg.) Y.Itô
• Pseudolobivia ancistrophora (Speg.) Backeb. ex Krainz

• Echinopsis ancistrophora Speg.
• Cereus pasacanus (F.A.C.Weber ex Rümpler) F.A.C.Weber
• Mesechinopsis ancistrophora (Speg.) Y.Itô
• Pseudolobivia ancistrophora (Speg.) Backeb. ex Krainz
• Echinopsis ancistrophora var. hamatacantha (Backeb.) Rausch
• Echinopsis hamatacantha Backeb.
• Mesechinopsis hamatacantha (Backeb.) Y.Itô
• Pseudolobivia hamatacantha (Backeb.) Backeb.
• Echinopsis ancistrophora var. megalocephala (Rausch) Rausch
• Echinopsis rauschii var. megalocephala Rausch
• Lobivia calorubra var. megalocephala (Rausch) Rausch
• Echinopsis ancistrophora var. polyancistra (Backeb.) Rausch
• Echinopsis polyancistra Backeb.
• Mesechinopsis polyancistra (Backeb.) Y.Itô
• Pseudolobivia polyancistra (Backeb.) Backeb.
• Echinopsis ancistrophora var. rubriflora Rausch
• Echinopsis leucorhodantha Backeb.
• Mesechinopsis leucorhodantha (Backeb.) Y.Itô
• Pseudolobivia leucorhodantha (Backeb.) Backeb. ex Krainz
• Echinopsis lobivioides Backeb.
• Echinopsis pelecyrhachis var. lobivioides (Backeb.) H.Friedrich
• Lobivia grandiflora var. lobivioides (Backeb.) Rausch
• Mesechinopsis lobivioides (Backeb.) Y.Itô
• Pseudolobivia lobivioides Backeb. ex Krainz
• Pseudolobivia pelecyrhachis var. lobivioides (Backeb.) Backeb.
• Echinopsis pelecyrhachis Backeb.
• Mesechinopsis pelecyrhachis (Backeb.) Y.Itô
• Pseudolobivia pelecyrhachis Backeb. ex Krainz
• Echinopsis subdenudata Cárdenas
• Echinopsis subdenudata f. cristata aurea hort.
• Echinopsis subdenudata f. cristata hort.

• Echinopsis ancistrophora subs. arachnacantha (Buining & F.Ritter) Rausch
• Echinopsis arachnacantha (Buining & F.Ritter) H.Friedrich
• Lobivia arachnacantha Buining & F.Ritter
• Echinopsis ancistrophora var. densiseta (Rausch) Rausch
• Echinopsis arachnacantha subs. densiseta (Rausch) M.Lowry
• Echinopsis arachnacantha var. densiseta (Rausch) Friedrich
• Lobivia arachnacantha var. densiseta Rausch
• Echinopsis ancistrophora var. kratochviliana (Backeb.) Rausch
• Echinopsis kratochviliana Backeb.
• Neolobivia kratochviliana (Backeb.) Y.Itô
• Pseudolobivia kratochviliana Backeb.
• Echinopsis ancistrophora var. sulphurea (R.Vásquez) Rausch
• Echinopsis arachnacantha subs. sulphurea (R.Vásquez) Lowry
• Echinopsis arachnacantha var. sulphurea (R.Vásquez) G.D.Rowley
• Lobivia arachnacantha var. sulphurea R.Vásquez
• Echinopsis ancistrophora var. torrecillasensis (Cárdenas) Rausch
• Echinopsis arachnacantha subs. torrecillasensis (Cárdenas) M.Lowry
• Echinopsis arachnacantha var. torrecillasensis (Cárdenas) Friedrich
• Echinopsis torrecillasensis Cárdenas
• Lobivia arachnacantha var. torrecillacensis (Cárdenas) Buining
• Pseudolobivia torrecillasensis (Cárdenas) Backeb.
• Echinopsis arachnacantha var. vallegrandensis Rausch

• Echinopsis ancistrophora subs. cardenasiana (Rausch) Rausch
• Echinopsis cardenasiana (Rausch) Friedrich
• Lobivia cardenasiana Rausch

• Echinopsis ancistrophora subs. pojoensis (Rausch) Rausch
• Lobivia calorubra var. pojoensis (Rausch) Rausch
• Lobivia pojoensis Rausch
• Echinopsis ancistrophora var. grandiflora (Rausch) Rausch
• Echinopsis rauschii var. grandiflora (Rausch) H.Friedrich
• Lobivia pojoensis var. grandiflora Rausch

Description: Echinopsis ancistrophoraSN|1041]]SN|1041]] is a striking Andean hookspined cactus of wide distribution showing extreme variation in flower colour and zize, with corolla lengths varying between 4.5 and 24 cm, and colour varying from white to dark-red. It is both solitary or forming clumps. Four subspecies are recognized, the nominate form subs. arachnacantha, subsp. cardenasiana and subs. pojoensis.
Stem: Simple, subglobose, depressed, 5 to 8 cm in diameter, shining dark green.
Ribs: 15-16(-20), stout, 1 cm high, broad at base, somewhat crenate, divided into many small tubercles.
Radial spines: 3 to 7(-10), whitish, slender, flexible, spreading backward, 5 to 15 mm long.
Central spine: Solitary, rarely as many as 4, sometimes absent, more or less curved or hooked, 1 to 2 cm long light brown.
Flowers: Inodorous, borne laterally, open during the day, usually white or tinged pink outside, but also pink to deep red, (4-)12 to 16(-24) cm long. Floral tubes slender. Outer perianth-segments greenish, linear, acuminate. Inner perianth-segments multi-coluored, oblong, acute. Scales of pericarpel and tube with axillary hairs. The shortest flowed forms usually have morning anthesis and low nectar production while the longer flowered forms open at dusk with prolific nectar. Sphingid moths are prevalent only in the populations with the longest corollas, and all other populations are mainly pollinated by solitary bees.
Fruit: Ellipsoid, dirty green to greenish purple, somewhat dry, 16 mm long, 8 mm in diameter. Scales on ovary and flower-tube small, their axils lanate.
Seeds: Spherical to ellipsoid, slightly constricted above the hilum, black, whit no aril.

Bibliography: Major references and further lectures.
1) Nathaniel Lord Britton, Joseph Nelson Rose “Cactaceae: Descriptions and Illustrations of Plants of the Cactus Family” vol. 1 The Carnegie Institution of Washington, Washington 1919
2) Edward Anderson “The Cactus family” Timber Press, Incorporated, 2001
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) Urs Eggli, Leonard E. Newton: “Etymological Dictionary of Succulent Plant Names” Birkhäuser 2004
6) Ortega-Baes, P. & Lowry, M. 2013. Echinopsis ancistrophora. The IUCN Red List of Threatened Species. Version 2014.2. <www.iucnredlist.org>. Downloaded on 03 August 2014.
7) E Haustein “Der Kosmos Kakteenfuehrer (the Kosmos Cactus Guide)” Balogh Scientific Books 01 December 1998
8) Pat Willmer “Pollination and Floral Ecology” Princeton University Press, 05/Jul/2011
9) Walter Rausch “Lobivia: The Day Flowering Echinopsidinae from a Geographical Distribution Point of View”, Volumes 1-3 R. Herzig, 1975
10) Willy Cullmann, Erich Götz (Dozent Dr.), Gerhard Gröner “The encyclopedia of cacti” Timber Press, 1987
11) John Pilbeam “Cacti for the Connoisseur: A Guide for Growers & Collectors” Timber Press, 01/Jul/1987
12) Carlos Luis Spegazzini “Cactacearum Platensium Tentamen.” In: Anales del Museo Nacional de Buenos Aires. 3(4): 492–493 1905
13) Martin Lowry: “Echinopsis.” In: Cactaceae Systematics Initiatives. 13: 16–17 2002
14) Succulenta.37,1956
15) Walter Rausch: Kakteen und andere Sukkulenten. 23(2): 32.1972
16) Heimo Friedrich: Kakteen und andere Sukkulenten. 25(4) 82. 1974
17) Urs Eggli, Leonard E. Newton: "Etymological Dictionary of Succulent Plant Names." Springer, Berlin/Heidelberg 2010
18) Zuloaga, F. O., O. N. Morrone, M. J. Belgrano, C. Marticorena & E. Marchesi: Monogr. Syst. Bot. Missouri Bot. Gard. 107: 3 Vols., 3348 p. 2008.

Cultivation and Propagation: Echinopsis ancistrophoraSN|1041]]SN|1041]] is a good beginner cactus and very easy to grow and flower. It is quite resistant and occasionally gets covered by bright showy yellow blossoms also neglected in a dry windowsill. Requires good drainage and very porous potting mix. Watering Needs Need regular water in spring to fall but do not water again until dry. Also, it is a species that is dormant in the winter and require very little water (maybe even none) during the cold months.
Frost Tolerance: Light frost protection required. Minimum of 5ºC for safe growing (but hardy up to -5°C or less) but some clones are hardy to lower temperatures. Requires to be kept below 7°C in winter to flower well in the spring.
Sun Exposure: Requires bright light (protect from strong midday sun). In shade the body colour will remain mostly green, while full sun will darken it and give it red/brown body colour. Can be sunburned if moved from shade/greenhouse into full sun too quickly. The amount of sunlight it can withstand without scorching depends upon the how hot it becomes in the summer in the locale in which it is planted. It will have more colour if it receives more light. During the spring it may be able to take full sun until the heat arrives at the end of spring. In an area that has hot afternoon sun, it may be able to take full morning sun, but requires afternoon shade or afternoon light shade.
Propagation: Seeds or offsets that appear at the base; leave them attached to form a cluster, or wait until they are 1/3 the size of the parent and then detach and plant.