Origin and Habitat: Salta and Jujuy, Argentina. Walter Rausch collected this plant in the Quebrada de Humahuaca in Jujuy (R214) and also in Salta and Catamarca (R751 and R823). Lau recollected it in Volcán between 3200 and 3300 m above sea level (L520) and Mats Winberg collected the var. tilcarensis in Tilcaras between 3100 and 3200m above sea level (MN163).
Altitude range: 3200-4000 metres above sea level.
Habitat and ecology: This cactus occurs on dry rocky outcrops in puna together with Lobivia sublimifloraSN|4662]]SN|12549]], Rebutia pseudodeminutaSN|4970]]SN|4970]], Lobivia jajoianaSN|12549]]SN|4662]].

• Rebutia euanthema (Backeb.) Buining & Donald
• Acantholobivia euanthema (Backeb.) Y.Itô
• Lobivia euanthema Backeb. in Backeb. & F.M.Knuth
• Mediolobivia euanthema (Backeb.) Krainz

• Rebutia einsteinii Frič in Möller
• Aylostera einsteinii (Frič ex Kreuz. & Buining) Mosti & Papini
• Cylindrorebutia einsteinii Frič ex Kreuz. & Jucker
• Lobivia einsteinii (Frič) Rausch
• Mediolobivia schmiedcheniana var. einsteinii (Frič) Backeb.
• Rebulobivia einsteinii Frič
• Mediolobivia auranitida var. flaviflora Backeb.
• Rebutia auranitida (Wessner) Buining & Donald
• Cylindrorebutia auranitida (Wessner) Bredero
• Lobivia auranitida Wessner
• Mediolobivia auranitida (Wessner) Krainz
• Rebutia brighignae Mosti & Papini
• Aylostera brighignae (Mosti & Papini) Mosti & Papini
• Rebutia einsteinii f. columnaris (Wessner) Buining & Donald
• Cylindrorebutia columnaris (Wessner) Bredero
• Lobivia columnaris Wessner
• Mediolobivia columnaris (Wessner) Krainz
• Mediolobivia conoidea var. columnaris (Wessner) Backeb.
• Rebutia conoidea var. columnaris B.Fearn & Pearcy
• Rebutia einsteinii var. columnaris (Wessner) Buining & Donald
• Rebutia einsteinii var. conoidea (Wessner) Buining & Donald
• Lobivia conoidea Wessner
• Mediolobivia conoidea (Wessner) Krainz
• Rebutia einsteinii f. conoidea (Wessner) Donald
• Cylindrorebutia conoidea (Wessner) Bredero
• Rebutia einsteinii f. karreri (Backeb.) Buining & Donald
• Mediolobivia schmiedcheniana var. karreri Backeb.
• Rebutia karrerii Frič in Möller
• Rebutia einsteinii f. rubriviridis (Frič ex Backeb.) Donald
• Mediolobivia schmiedcheniana var. rubriviridis Frič ex Backeb.
• Rebutia einsteinii var. steineckei (Backeb.) Buining & Donald
• Mediolobivia schmiedcheniana var. steineckei Backeb.
• Rebutia euanthema f. neopygmaea (Backeb.) Buining & Donald
• Mediolobivia neopygmaea Backeb.
• Rebutia fischeriana Slaba
• Aylostera fischeriana (Slaba) Mosti & Papini
• Rebutia nicolaii Frič in Möller
• Cylindrorebutia nicolai Frič
• Mediolobivia einsteinii f. Nicolai hort. sensu Frič, Donald
• Rebulobivia nicolai Frič & Kreuz.

• Rebutia einsteinii subs. aureiflora (Backeb.) Hjertson
• Aylostera aureiflora (Backeb.) Mosti & Papini
• Lobivia aureiflora (Backeb.) H.P.Kelsey & Dayton
• Mediolobivia aureiflora (Backeb.) Backeb.
• Rebutia aureiflora Backeb.
• Mediolobivia aureiflora var. carminata (Backeb.) Backeb.
• Mediolobivia carminata Backeb. ex Krainz
• Mediolobivia aureiflora var. longiseta Backeb.
• Lobivia longiseta (Backeb.) H.P.Kelsey & Dayton
• Mediolobivia longiseta (Backeb.) Backeb.
• Mediolobivia aureiflora subvar. leucolutea Backeb.
• Mediolobivia aureiflora subvar. lilacinostoma Backeb.
• Mediolobivia rubriflora var. compactiflora (Wessner) Krainz
• Mediolobivia blossfeldii var. compactiflora Wessner
• Mediolobivia rubriflora var. nigrilongiseta (Wessner) Krainz
• Mediolobivia blossfeldii var. nigrilongiseta Wessner
• Mediolobivia turbiniformis Backeb. ex Frič & Kreuz.
• Setirebutia turbiniformis Frič
• Rebutia aureiflora var. albiseta (Backeb.) Borg
• Mediolobivia aureiflora var. albiseta Backeb.
• Setirebutia albiseta (Backeb.) Frič ex Kreuz.
• Rebutia aureiflora var. albi-longiseta (Backeb.) W.T.Marshall
• Mediolobivia aureiflora var. albi-longiseta Backeb.
• Mediolobivia longiseta var. albi-longiseta Backeb.
• Rebutia aureiflora var. blossfeldii (Werderm.) Donald
• Mediolobivia blossfeldii (Werderm.) Buining
• Mediolobivia rubriflora var. blossfeldii (Werderm.) Krainz
• Rebutia blossfeldii Werderm.
• Rebutia aureiflora f. boedekeriana (Backeb.) Šída
• Mediolobivia aureiflora var. boedekeriana (Backeb.) Backeb.
• Mediolobivia boedekeriana Backeb.
• Rebutia aureiflora f. duursmaiana (Backeb.) Šída
• Mediolobivia aureiflora var. duursmaiana (Backeb.) Backeb.
• Mediolobivia duursmaiana Backeb.
• Rebutia aureiflora var. elegans (Backeb.) Buining & Donald
• Mediolobivia elegans Backeb.
• Rebutia aureiflora subs. elegans (Backeb.) Donald
• Rebutia einsteinii var. elegans (Backeb.) Rausch
• Rebutia aureiflora f. kesselringiana (Cullmann) U.Köhler
• Mediolobivia kesselringiana Cullmann
• Rebutia aureiflora var. blossfeldii f. kesselringiana (Cullmann) Donald
• Rebutia aureiflora f. rubelliflora (Backeb.) Buining & Donald
• Mediolobivia aureiflora var. rubelliflora (Backeb.) Backeb.
• Mediolobivia rubelliflora Backeb.
• Rebutia aureiflora f. rubriflora (Backeb.) Buining & Donald
• Mediolobivia aureiflora var. rubriflora (Backeb.) Backeb.
• Mediolobivia rubriflora Backeb.
• Rebutia aureiflora f. sarothroides (Werderm.) Buining & Donald
• Mediolobivia aureiflora var. sarothroides (Werderm.) Backeb.
• Mediolobivia sarothroides (Werderm.) Buining
• Rebutia aureiflora var. sarothroides (Werderm.) Donald
• Rebutia sarothroides Werderm.
• Rebutia euanthema (Backeb.) Buining & Donald
• Acantholobivia euanthema (Backeb.) Y.Itô
• Lobivia euanthema Backeb. in Backeb. & F.M.Knuth
• Mediolobivia euanthema (Backeb.) Krainz
• Rebutia euanthema f. fricii (Backeb.) Buining & Donald
• Mediolobivia euanthema var. fricii Backeb.
• Rebutia oculata Werderm.
• Aylostera oculata (Werderm.) Mosti & Papini
• Mediolobivia euanthema var. oculata (Werderm.) Krainz
• Rebutia euanthema f. oculata (Werderm.) Buining & Donald
• Rebutia oculata subs. tilcarensis (Rausch) Mosti
• Aylostera oculata subs. tilcarensis (Rausch) Mosti & Papini
• Lobivia euanthema var. tilcarensis Rausch
• Rebutia tilcarensis (Rausch) Šída
• Rebutia orurensis (Backeb.) F.Ritter
• Aylostera orurensis (Backeb.) Mosti & Papini
• Digitorebutia haagei var. orurensis (Backeb.) Donald
• Digitorebutia orurensis (Backeb.) Buining
• Lobivia orurensis Backeb. in Backeb. & F.M.Knuth
• Mediolobivia haagei var. orurensis (Backeb.) Donald
• Mediolobivia orurensis (Backeb.) Backeb.
• Mediolobivia pectinata var. orurensis (Backeb.) Backeb.
• Setirebutia disciformis Frič

• Rebutia einsteinii subs. gonjianii (R.Kiesling) Hjertson
• Aylostera gonjianii (R.Kiesling) Mosti & Papini
• Cylindrorebutia gonjianii (Wahl)
• Digitorebutia einsteinii var. gonjianii
• Digitorebutia gonjianii (Wahl)
• Lobivia einsteinii var. gonjianii (R.Kiesling) Rausch
• Lobivia gonjianii (R.Kiesling) R.Kiesling
• Mediolobivia einsteinii var. gonjianii
• Mediolobivia gonjianii hort. sensu R.Kiesling
• Rebutia einsteinii var. gonjianii (R.Kiesling) Donald
• Rebutia gonjianii R.Kiesling
• Rebutia einsteinii subs. gonjianii f. cristata hort.
• Rebutia eichlami var. gonzalesii f. cristata hort.
• Rebutia gonjianii f. cristata hort.

Description: Rebutia euanthemaSN|11210]]SN|4400]] is a popular species with very showy orange-red flowers, with small stems freely offsetting from the base forming clumps 70-80 mm in diameter. The spines are always slightly erect never appressed. Rebutia euanthemaSN|4400]]SN|4400]] is one of the morphological or local forms of Rebutia einsteinii subs. aureifloraSN|4393]]SN|4393]], and the two plants are not readily distinguishable, if not for the geographical provenance. More likely they are one and the same species. Also, you can include Rebutia euanthemaSN|4400]]SN|4400]] as a synonym of Rebutia einsteinii subs. gonjianiiSN|4400]]SN|11210]], as at the top of the Quebrada de Purmamarca the red-flowered R. euanthema gradually merges into the yellow-flowered R. einsteinii subs. gonjianii.
Stem: Up to 30 mm in diameter (often more in cultivation), grey-green often tinged amethyst.
Areoles: Elliptical, light brownish in colour.
Radial spines: About 10, often pectinate, always slightly erect never appressed, up to 10mm long, white tipped brown.
Centrals spines: Absent.
Flowers: About 45 mm long and 30mm wide with orange-red petals. Flower tube very hairy with occasional bristles. Stigma and style greenish-yellow, 6-lobed, filaments lavender pink.
Fruit: Brownish-red, densely covered with white hairs.
Seeds: Dull brownish-black.

Bibliography: Major references and further lectures
1) D. Hunt, “Cactaceae Systematics Initiatives” Bulletin of the International Cactaceae Systematics Group, 1996
2) Brian Fearn and Leslie Pearcy “The Genus Rebutia 1895—1981” No. 2 of a series of illustrated guide books, Published by Abbey Brook Cactus Nursery 1981

Cultivation and Propagation: Rebutia euanthemaSN|4400]]SN|4400]] is a summer grower species that is easy to cultivate.
Growth rate: It is a relatively rapidly growing and easily flowering species that will make clumps given the best conditions.
Soils: It likes very porous standard cactus mix soil. Prefer a neutral or low pH compost, avoid substrata rich in limestone.
Repotting: It is better that they are repotted regularly. Repotting will increase the number and size of stems and will increase the number of flowers produced. Repot yearly until reaching about 100mm in size, then every two or three years will suffice. Repotting is best done at the end of winter but can be done at other times. Do not water for a couple of weeks after repotting to reduce risk of root rot via broken roots. Use pot with good drainage.
Watering: Needs moderate to copious waterings in summer, but do not overwater (Rot prone), keep dry in winter at a minimum temperature of 0°C.
Fertilization: Feed with a high potassium fertilizer in summer.
Hardiness: Reputedly resistant to frost if kept on the dry side prior to, and during, cold weather (hardy to -4 C ° C, or less for short periods).
Exposition: The plant tolerates bright situations but enjoys filtered sunlight or afternoon shade, inside it needs bright light, and some direct sun. Tends to bronze in strong light, which encourages flowering and heavy spine production, but is likely to suffer from sun scorch or stunted growth if over exposed to direct sunlight during the hottest part of the day in summer.
Uses: It is an excellent plant for container growing. It always looks good and stays small. It look fine in a cold greenhouse and frame or outdoor in a rockery.
Pests & diseases: It 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 watering the plants from above.
- Mealy bugs: Mealy bugs occasionally develop aerial into the new growth among the wool with disfiguring results, but the worst types develop underground on the roots and are invisible except by their effects.
- Scales: Scales are rarely a problem.
- Rot: This species is particularly easy and accommodating, seldom suffer of cryptogamic diseases. Rot it is only a minor problem with rebutias if the plants are watered and “aired” correctly. If they are not, fungicides won't help all that much.
Propagation: Division, direct sow after last frost. Seeds germinate in 7-14 days at 21-27° C in spring, remove gradually the glass cover as soon the plants will be well rooted (ca 1-2 weeks) and keep ventilated, no full sun for young plants! Seed Collecting: Permit fruit to ripen. Fruit must be significantly overripe before harvesting seed; clean and dry seeds. To make a cutting twist off a branch and permit it to dry out a couple of weeks, lay it on the soil and insert the stem end partially into the soil. Try to keep the cutting somewhat upright so that the roots are able to grow downward.