Accepted Scientific Name: Mammillaria lasiacantha subs. magallanii (F.Schmoll ex R.T.Craig) D.R.Hunt
Mammillaria Postscripts 6: 7 (1997)
Mammillaria roseocentra Photo by: Silvio Fantuzzi
SB444 (Collector: Steven Brack) Locality: Lerdo, Durango, Mexico
Origin and Habitat: Durango and Lerdo (also Coahuila and Baja California ?), Mexico
Ecology: The dense addpressed spination of Mammillaria roseocentraSN|9251]]SN|9251]] serves 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.
Synonyms:
See all synonyms of Mammillaria lasiacantha
Description: Mammillaria roseocentraSN|9075]]SN|9251]] is a controversial species considered by Pilbeam a form of Mammillaria magallaniiSN|9244]]SN|9244]], but the original description of M. roseocentra calls for 25 radial spines only and it is more likely that the name has subsequently been misapplied. It is a small slow growing species with tight, radial spines, in two rows, short, especially the inside one, initially beautiful pink, at the apex almost red then creamy white. It has attractive little creamy-pink blooms and red fruit, and is similar to Mammillaria lasiacanthaSN|9251]]SN|9075]].
Habit: Plants usually solitary with a succulent tap root. With age it may offset from the base to form a small cluster.
Stem: Without latex, globose, to club shaped, green, to 6 cm tall and 4,5 cm in diameter.
Tubercles: Short-cylindrical, without latex. Axils bare.
Radial spines: About 25, but usually much more numerous, interlacing, 2 - 5 mm long, chalky white to very pale pinkish-brown which are pinkish or reddish towards the growing point.
Central spines: Usually absent.
Flower: Cream coloured with pinkish-red or pinkish-brown midribs, to 10 mm long and in diameter.
Blooming season: Early spring (February–March in habitat).
Fruit: Red and very showy.
Subspecies, varieties, forms and cultivars of plants belonging to the Mammillaria lasiacantha group
- Mammillaria lasiacantha Engelm.: Single or forming Small clusters of 2 or 3 heads. Stems are spherical usually less than 5 cm in diameter. They usually have soft glabrous spines, but in some populations all plants may retain plumose spines at maturity.
- Mammillaria lasiacantha var. denudata Engelm.: has always glabrous spines. For all other characteristics it is comparable to the standard Mammillaria lasiacantha. Distribution: Big Bend National Park (Brewster County), Texas.
- Mammillaria lasiacantha subs. egregia (Backeb. ex Rogoz. & Appenz.) D.R.Hunt: It forms small snow-white ball, usually unbranched, deep-seated in substrate and inconspicuous that become somewhat cylindrical with age up to 5 cm in diameter × 2-7 cm tall.
- Mammillaria lasiacantha subs. egregia f. cristata hort.: crested form. It will slowly forms white tangled groups up to 10 cm in diameter.
- Mammillaria lasiacantha subs. hyalina D.R.Hunt
- Mammillaria lasiacantha subs. magallanii (F.Schmoll ex R.T.Craig) D.R.Hunt: Small usually solitary slow growing species with short white spines. Stems globose to club shaped, green, up to 6 cm tall and 4.5 cm in diameter. Distribution: Coahuila and Durango.
- Mammillaria lasiacantha f. wohlschlageri (Repp.) Hoeve: Small plants with a flat fuzzy stem and creamy flowers blooming abundantly in late winter-to early spring. Radial spiness 26-36, glassy white, brown tipped, 2 - 6 mm long.
- Mammillaria magallani var. hamatispina Backeb.: 50-70 creamy-yellowish radial spines with one hooked darker central spine.
- Mammillaria neobertrandiana Backeb.: Nice pink spines, the small winter flowers are pale pink with a pink/brown midstripe. Distribution: Lerdo, Durango.
- Mammillaria roemeri Wolfg.Krüger & W.Rischer: It is a neotonic (juvenile form which remains so) form of Mammillaria lasiacantha. The flower position and its later flowering distinguish it, as well as the spination. It looks different, but clearly related.
- Mammillaria roseocentra Boed. & F.Ritter: radial spines numerous, in two rows, short, especially the inside one, initially beautiful pink, at the apex almost red: Distribution: Durango and Lerdo, Mexico
- Mammillaria sp. f. cristata SB500 Cuatrocienagas, Coahuila, Mexico: is a tiny crest form that may retain plumose spines at maturity.It slowly forms tangled groups up to 20 cm in diameter.
- Mammillaria sp. SB500 Cuatrocienagas, Coahuila, Mexico hort., S.Brack: (M. lasiacantha) Feathery form with tiny stems that resemble golf balls.
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
2) David R Hunt; Nigel P Taylor; Graham Charles; International Cactaceae Systematics Group. "The New Cactus Lexicon" dh books, 2006
3) John Pilbeam “Mammillaria: the cactus file handbook” Cirio Publishing Services Ltd Dec/30,/1999
4) John Pilbeam “Cacti for the Connoisseur: A Guide for Growers & Collectors” Timber Press, 01/lug/1987
5) Walther Haage “Kakteen von A bis Z” Neumann Verlag , 1981
Cultivation and Propagation: This plant has not the fame to be easy to cultivate, but in good conditions with very careful application of water and excellent ventilation, it grows without difficulty. Be careful to encourage slow growth, but if you succeed in growing a colony of stems, then the results will repay all the growing efforts.
Growing rate: It is a slow growing species that will make clumps given the best conditions, but rewards the patient grower with a beautiful displays of flowers since from an early age.
Soil: Requires excellent drainage provided by a very permeable open cactus soil (With not less than 50% grit content). Avoid the use of peat or other humus sources in the potting mixture.
Repotting: Repot every 2-3 years. Use small sized pots.
Feeding: During the beautiful season enrich the soil using a fertilizer rich in potassium and phosphorous, but poor in nitrogen, because this chemical element doesn’t help the development of succulent plants, making them too soft and full of water.
Watering: Water should be carefully applied and only when the soil is dry to the touch, as this cliff-dwelling species is very prone to root rot. Allow soil to drain thoroughly before watering again. Additionally, water should not be applied from above, as the feathery spines will retain water and add to rotting problems, but in good conditions with excellent ventilation, in bright light, it usually grows without particular difficulty. Do not water in the winter.
Light: Outside full sun or afternoon shade, inside it needs bright light, and some direct sun. Direct sun encourages flowering and heavy spine production.
Hardiness: Protect from frost. But it's hardy to -5°C if kept dry. A winter rest that allows the plant to shrivel (perhaps losing up to 25% of its summer height) will encourage flowering and long time survival.
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 misting the vulnerable plants every day
- Mealy bugs: occasionally they 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: it is only a minor problem with cacti if the plants are watered and “aired” correctly. If they are not, fungicides won't help all that much.
Propagation: Direct sow after last frost or (rarely) cuttings. 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!