Accepted Scientific Name: Cleistocactus baumannii subs. chacoanus (F.Ritter) P.J.Braun & Esteves
Succulenta (Netherlands) 74: 84. 1995
Origin and Habitat: Margarita and adjacent areas, Tarija, Bolivia
Altitude: Around 1800 metres above sea level.
Synonyms:
See all synonyms of Cleistocactus baumannii
Description: Cleistocactus margaritanusSN|4742]]SN|18174]] a shrubby columnar cactus, branching basally with several stems. It has attractive yellowish bristly soft spines and orange-red S-shaped blooms, and seems related to Cleistocactus baumanniiSN|18174]]SN|4742]] subs. chacoanus. The most striking feature is the dense, golden yellow spination it possesses, which serve to protect it from the harsh sun common to its native habitat. More precisely the spines benefit the plant by reducing sun exposure and by trapping a layer of air next to the cactus body. This helps to cool the plant in the summer and keep it warm in the winter.
Stems: Fairly stiff, erect or arching, to 2 m or more long, about 3,5 cm in diameter.
Ribs: About 16.
Areoles: Close set.
Spines: Several, golden yellow not differentiated as centrals and radials, straight, soft, and bristly.
Flowers: Tubular, bilaterally symmetrical, curving upward, then narrowly S-haped above the pericarpels, orange-red 5-7 cm long, to 1 cm in diameter; perianth parts oblique; stamens red; stamens and style exserted. Stigma lobes green.
Fruits: Globose, red.
Subspecies, varieties, forms and cultivars of plants belonging to the Cleistocactus baumannii group
- Cleistocactus baumannii (Lem.) Lem.: (subsp. baumannii) has 15-20 radial spines and red flowers. Distribution:Northeastern Argentina, Paraguay, and Uruguay.
- Cleistocactus baumannii subs. anguinus (Gürke) P.J.Braun & Esteves: decumbent with 10-11 radial spines and yellow-orange or orange-red flowers. Distribution: Paraguay.
- Cleistocactus baumannii subs. chacoanus (F.Ritter) P.J.Braun & Esteves: has more erect shoots, with less ribs, 12-15 radial spines and shorter bilaterally symmetrical flowers, usually red. Distribution: Gran Chaco region of Bolivia.
- Cleistocactus baumannii subs. croceiflorus (F.Ritter) P.J.Braun & Esteves: has 8-12 radial spines and yellow flowers. Distribution: Puerto Casado, Alto Paraguay department, Paraguay.
- Cleistocactus baumannii subs. horstii (P.J.Braun) N.P.Taylor: has 11-15 radial spines and bilaterally symmetrical flowers, orange-red. Distribution: Mato Grosso do Sul, Brazil.
- Cleistocactus baumannii var. paraguariensis (F.Ritter) P.J.Braun & Esteves: 12-15, yellow to reddish yellow with darker tips, and 4-5, reddish brown centrals. Distribution: Paraguari department, Paraguay.
- Cleistocactus baumannii subs. santacruzensis (Backeb.) Mottram: has fewer but more elevated ribs, only about 10 radial spines and red flowers (perhaps the same as subsp. anguinus), Anthers barely protruding. Distribution: Santa Cruz, Bolivia.
- Cleistocactus bruneispinus Backeb.: has brown spines. Distribution Cochabamba, Bolivia.
- Cleistocactus margaritanus hort.: has dense yellowish bristly soft spines and orange-red S-shaped blooms, and seems related to subs. chacoanus. Distribution: Margarita, Tarija, Bolivia
- Cleistocactus margaritanus f. cristatus hort.: crested form.
Bibliography: Major references and further lectures
1) Edward Anderson “The Cactus family” Timber Press, Incorporated, 2001
2) 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
3) David R Hunt; Nigel P Taylor; Graham Charles; International Cactaceae Systematics Group. "The New Cactus Lexicon" dh books, 2006
Cultivation and Propagation: Cleistocactus margaritanusSN|18174]]SN|18174]] is of easy culture, which makes it a good cactus for beginners. It suited to hanging baskets as well as pots.
Soil: Use a loose well drained cactus mix.
Repotting: Since they are rapid growers need plenty of space for their roots, repotting with fresh potting-mix should be done every other year or when the plant has outgrown its pot. However, repotting doesn't necessarily mean they'll need larger containers.
Sun Exposure: Require filtered bright light, partial sun or light shade, but not in full sun that will sunscald it.
Watering: They require moderately watering through the growing season. This can be done weekly or more frequently during the summertime, if the weather is sunny enough, but allow to dry fully before watering again. Kept this way, plants will show a healthy growth. Keep rather dry as soon as the temperature starts dropping in October and keep it dry in winter. The plant survives outside without protection in winter (cold hardy to -2° ) but is then somewhat prone to rot, too.
Fertilization: Give an occasional high potassium liquid feed during the active growing period.
Hardiness: Winter care presents no problems at temperatures from 5 to 15 degrees centigrade with plenty of light, but frost hardy to -2°C for short periods if very dry. This plant needs a period of cool rest in winter to produce flowers abundantly. It flowers freely indoors too if conditions suit it.
Pest and diseases: They are generally fairly easy to grow, especially if kept pest-free. They are susceptible to, scale insects and spider mite. Watch carefully for infestations of stem and root mealy bugs, and damage from these may well initiate fungal attack.
Propagation: Easy to propagate from cuttings or seeds. Take cuttings spring or summer, let them dry till the ends callous well. Then replant them in fresh cactus soil that is ever so slightly moist, and keep it that way till they root. Surface sowing is the best; seeds germinate in 14-28 days at 20° C , remembering that seedlings dislike strong light and dry conditions.