You are here:

Cactus/classification

Advertisement


Question

my cactus
What kind of cactus is this? I'm really desperate, I've been poking around for hours but I haven't found any definite information. Please help!

Answer

Melocactus
Dear Emily,

I believe you have a young melocactus there.  When mature it will develope a cephalium, a wool- and bristle-coated structure at the apex of the plant. They can take a long time to mature and are somewhat difficult to ID until they do.  The cluster of spines at the top of your cactus precede the cephalium. They are slow growers and can take 7 or more years for the latter to develop. Their characteristic cephalium and are charctristic  only of Melocactus, and the similar genus Discocactus. This is a permanent, apical, hatlike appendage.  Cylindrical, with a diameter distinctly smaller than that of the plant body below, the cephalium will keep growing for the rest of the plant’s life, but the body of the plant stops growing the moment the cephalium starts to form. As the plants age the cephalium doesn't increase in circumference it will steadily grow taller.

I don't know specifically which of the approx. 40 plants in the Genus you have but if you have time google it and see if you can find yours. It's hard when young to ID.

 
Cultivation: These cacti are not the easiest things to grow and aren’t generally plants for beginners. I rarely pay attention to that warning, sometimes to my regret.

Melocactus grows from April to October, it can’t endure long stretches of total dryness, and also too much water will rot it, as its weak root systems tend to be inefficient at sucking up water from wet soil. Nonetheless, again as a result of their tropical origins, they need a fair amount of water, but allow the soil to dry quite a bit before watering again. Melocactus rests from October to April but can’t stand cold, or even fairly cool temperatures, tho I do keep mine in a room that is about 50-60 degrees and DON'T water it when it is dormant. It isn't the hardiest of plant so can't tolerate the very cold temps that most dormant cacti can. The literature says they prefer prefer more frequent water in winter than other cacti, say once a month. I just mist mine, but perhaps you should go by the literature. Do not feed in winter.

Since the root system is weak it generally resents being repotted and can take a long time to re-establish. The soil mix should be very quick draining, prefers very bright light, not as much as the most arid growing cacti, but plenty nonetheless. How long has yours been in that pot?  If more than a couple of years I WOULD repot and put it in a smaller, azalea type pot at that.

Let me see if I can attach a picture of a mature plant (not yours specifically).  If it doesn't come through, they are easy to find on the net.

So don't feel bad for all that poking.  Young plants look like  lot of other barrel cactus.

Hope this helps.

Maureen
    Questioner's Rating
    Rating(1-10)Knowledgeability = 10Clarity of Response = 10Politeness = 10
    CommentThanks so much! You've saved my hours of looking through cactus photos!


  • Add to this Answer
  • Ask a Question

Maureen

Expertise

I can answer questions regarding the care and propagation of cactus and succulents and would actually group these together as folks often mistake one for the other and often their care is quite different. I also have a cold hardy cactus and succulent garden that has been quite successful. The subject in regard to classification of type is enormous and I wouldn't be able to answer all questions by any means. It is really IMPORTANT TO INCLUDE A PHOTO if at all possible and LET ME KNOW WHERE YOU ARE FROM, especially in terms of climate.

Experience

I have learned by reading books, by trial and error and by consulting with folks with much more knowledge. I have primarily grown C&S for the last 20 years.

Organizations
Cactus and Succulent Society of Massachusetts.

Education/Credentials
No formal training. See experience.

©2012 About.com, a part of The New York Times Company. All rights reserved.