Growth Habits: This cactus normally has a solitary body (but like anything else in nature there are exceptions to the rule). It usually attains a size of 4 to 6 inches wide (10-15 cm), 20 inches tall (50 cm); with 15 to 18 prominent ribs; close set areoles; 1 to 4 central spines, up to 0.6 inch long (1.5 cm), in the classical look, the spines are straight and give a comb-like effect. The plant has what looks like a waxy coating covered with pores and if looked at close has a strange resemblance to human skin
Scientific name: Uebelmannia pectinifera
Common names:Not known.
Synonym: Uebelmannia pectinifera var. pseudopectinifera, Uebelmannia pectinifera var. multicostata
Etymology: Named after Werner Uebelmann, the Swiss nurseryman who imported them into Europe. Pectinifera refers to the comb-like spines of the plant.
Origin: Brazil (mountain of Minas Gerais)
Light: The plant will take full sun for half a day, but does like a little shade for part of the day. If you can place it so that this occurs the plant will be much happier.
Compost: I feel like I am repeating myself every month and I am sure most of you have got the message that 99% of cacti need a good open compost. Admittedly with some plants you may get away with a ‘heavier’ mix, but with this plant if you do not have a perfectly free draining compost, you are committing it to a watery grave. Many sources advocate the addition of some limestone to the mix.
Water: The plant like me, likes a good drink now and again, but is prone to rot at the base, particularly if the weather is cool. To help stop this a good deep collar of gravel or chicken grit is an excellent idea.
Flower: The flowers if you are lucky enough to get them, bloom in summer and are yellow and funnel-shaped, with no discernible scent.
Fruit: The fruit is insignificant, dark red and globular
Min. temp: This plant like most of the Melocactus will not stand the cold in any shape or form. Even keeping it frost free is courting disaster. The plant must be kept no lower than 50°f. 10°c year round and many sources say an all round temperature of at least 59°f. is not too high.
Cultivation: The plant is often grafted because of its tendency to rot at the base. If possible a rootstock that is more hardy than the Uebelmannia is the ideal. The plant loves warm humid conditions and mist spraying is a must in summer.
Habitat: Minas Gerais was formerly inhabited by colonists who dug for gold and gems and later diamonds, so it is quite appropriate that a gem of the cactus world grows there. It is also the source of some of the largest rivers in Brazil. The central and eastern areas are hilly and rocky. Some of the mountains are almost pure iron ore.
Comments: This really is a beautiful cactus and is worth a place in any collection. It is not the easiest to keep looking healthy, or alive for that matter, but is well worth the effort. 30 years ago the plant would probably have cost you a couple of hundred US dollars, £80 or £90, but the professional growers now seem to be able to propagate them quite quickly, although they will still cost you quite a lot more than the average cacti.
Photograph by kind permission of David Angus http://www.botanica.uk.net/cacti.htm