Request information about Mammillaria roemeri -thank's-

Good morning (2).

I will sow some seeds of Mammillaria roemeri.
I have great difficulty to find some informations on this species.

I learned from a member of another forum, that the New Cactus Lexicon puts it in the Genius lasiacantha-strong form of neotenic of...-.
Do you agree with this definition ?

Have you ever performed sowing of this species?
What advice can you give me ?

Thank you very much.

Hello Anna,
I bought two grafted plants in Russia (!) in the summer of 1997, just after I had sown 10 seeds of M. roemeri that I bought from Koehres in Germany.
Why Russia? a long story, but I had found them on a website but had difficulty contacting the seller. Another UK enthusiast also wanted this plant, so he tried as well. My wife and I were going on a River cruise from St. Petersburg to Moscow, and when I got off the boat at Moscow, there were two people with a sign saying "Cacti for Chris". I had given my friend the details of my holiday,just in case he got a reply while I was away. And so it all worked, 2 plants for him and 2 for me.
I have taken them off their grafts now and they rooted very easily.
Of the seeds I only had one germinate, but it grew quite quickly and is now of flowering size as well. I didn't do anything special, my usual method of seed raising.
As to their taxonomy? I know David Hunt's view. He and I have exchanged emails over this. I see that there is some resemblance, but my personal view is that they are at least as distinct as gasseriana is from lasiacantha. The spination is different, the flowering is from old axils only, a distance down the plant body, similar to where M. crucigera flowers, and the flower shape is different too.
I keep them separate in my collection, and though they are placed next to the others of the Lasiacanthae, it is very easy to see the difference.

Good
evening.
Kris ,thank you for your very detailed reply.
For their taxonomy, perhaps
one day, genetics has the last word.

I admire your determination in finding your plants
Mammillaria roemeri .
I simply buy some seeds from Koehres.
I hope to draw
some seedlings.......Fingers
crossed.

I have sown seed of M.roemeri which has come from Koehres for the last 3 years and I have never had any germination. I sowed another packet of seed last Monday with nothing showing at the monment.
I have never seen seed for sale from any other source than Koehres.

Hello tam.
Thank you for sharing your experience. I hope I have better luck than you, I hope I have more luck than you, but I tremble....

Like you, I have found that seeds from Koehres.
I think I have seen some grafted plants for sale on the web site of Kakteen Piltz.

I wish you success for your second test. A short week, there's still hope, dont you think?

I think sow the month of May, when I leave the seedlings in 2009 of my
"seedlings-box".
I'll keep you posted. To be continued ....

Good weekend to every body.

I've sown 50 seeds of M roemerii (from Koehres) about 2 weeks ago and today I noticed my first seedlings. A few years (3?) before I've sown 10 seeds and I had 2 seedlings from this batch. One of these was in flower last week.

Wiebe

The germination of M. roemeri is very problematic!!! In the spring of 2009 I spoke with Wolfgang Krüger (one of the discoverers of M. roemeri) and he told me that only 10% of habitat collected seed gave germination, whereas seed obtained from greenhouse plants gave 0% germination.
I received quite a few seeds from Wolfgang Krüger and indeed, I got 0% germination. About half a year earlier, I had also received some (habitat collected) seed from Thomas Linzen and these seeds were sown a year ago. At first there was no germination. The temperature in the propagator was gradually increased over about a month, from 20 to 40 degrees C, and then finally, at those high temperatures I got some germination, with the result that I have 5 seedling plants at the moment.
A week ago, I have sown more of the seeds which I received from Wolfgang Krüger in 2009 (now at 35 degrees C from the start). Hopefully, I get some germination from these seeds as well....
M. roemeri grows in a very calcareous area, in a region which experiences higher temperatures (certainly in the winter) than in M. lasiacantha and M. stella-de-tacubaya territory. I saw the plants in habitat in February 2009, they were very, very dehydrated (they looked dead, and probably many were) and there had not been any rain at all for several months. According to Wolfgang Krüger it sometimes looks like there is hardly a plant left, but then the next year you may find many plants, and so they reproduce and grow quite well in habitat, depending on the circumstances.
M. roemeri is distinct enough to give it a separate status (whether species or subspecies or variety).

Wolter.

Hello.
wiebe and woltertenhoeve, thank you for your responses.

Ouch! I chose 30 seeds of a Diva .... !! I tremble a little more !

Thank you for the advice about the temperature, woltertenhoeve.
Echinocactus horizonthalonius, which is not very easy either,
also seems to germinate better under high temperatures (to
verify).
That makes me think .... : Currently, in France, more and more fans of sowing cacti considered difficult (Eriocyse, Echinocactus horizonthalonius, Puna, etc ...), use of highly concentrated sulfuric acid with successes in apparently.
Personally, I do not use : This product is very dangerous, especially for
a clumsy like me.
Have you ever tried with Mammillaria difficult ?
Good night at all.

woltertenhoeve, Thank you also for your opinion on the status of Mammillaria roemeri and the information on its habitat.

Bonjour Anna,

I have never tried to treat Mammillaria seeds with sulfuric acid. As a professional chemist I am used to work with concentrated sulfuric acid and it certainly is an agressive chemical. If you spill some on your hands, you need to wash with water (the spot where you spilled it, will get warm and it makes you go to the water tap). If you spill some on your clothes, then you will notice it by the hole which is produced after a while. Never add water to sulfuric acid (will cause splashing), but always add sulfuric acid to water.
Do you know how long they treat the seeds with sulfuric acid? Seconds, minutes?
Has anyone ever tried to use sulfuric acid for other difficult to germinate Mammillarias like theresae, goldii, saboae, luethyi? Or does someone have a good method to germinate seeds of those species? I got my best (still rather poor) results when I kept the sowing pot (wet, in a plastic bag) high in the greenhouse for a few months , i.e. at high temperature.
Echinocactus horizonthalonius indeed germinates better at high temperatures, but if you keep the seeds wet for a too long time, then the seeds will simply rot.

Wolter.

I've only tried roemeri from seed, not those of the saboe complex or luethyi. I have heard that treating difficult to germinate seeds (not specifically Mammillaria) with giberellic acid (a plant hormone) can help, though I've never tried it.
A number of years ago, I germinated seeds of Pediocactus and Sclerocactus by "chitting" them. This is the process when you take a very sharp blade and slice a very little off the outer coating of the seed - not enough to damage it but just to weaken or ideally expose the inside. Of course I then kept them too wet and they rotted, mostly.
I don;t know whether this would work with these Mammillaria seeds, which are probably a bit smaller that Pediocactus as well.

Hello

Woltenhoeve and Chris, I will not attempt to manipulate Vitriol.
Again, too dangerous in my opinion.

Moreover it does not strike me as very important results have been obtained on the Divine Diva Saboae Group and M luethyi.

About the time of contact, I put a link to a story of the CF
(French language forum, which I love).

http://www.cactuspro.com/forum/read.php?1,


The first table does not work, but those on page 2 yes.

Thank you for your generous sharing of experience.
Good Sunday.

I would not recommend using Sulphuric acid has this would be to dangerous to both yourself and the seed.
When I worked on a tree and shrub nursery we would the soak the seeds in Hydrochloric acid from between 5 minutes and 2 hours depending on what species we were sowing. This breaks down the testa (seed coat) to allow water a greater chance to pentrate to the embryo inside.
Giberellic acid, being a growth hormone, would have no effect in aidding germination at this point. We used it has a weak solution to water over the tops of rooted cuttings to help speed up the rooting process.
In regard to the soboae complex. I believe it is not a matter of the testa (seed coat) being to hard but the lenght of time it takes the embryo to develope.
It might make for an interest test for next year, has I have sown my seed of these species for this year and of course if I could get hold of some Hydrochloric acid.

Hi Tam. What worries those little seeds
....
I wish you success in your planting saboae.
For complex I
wonder if the freshness of the seeds would not (for once) a disability
for germination.
I am developing:
I have very little experience in the seedling cacti, but I noticed
that none of the seeds from my own Mammillaria saboae never germinated,
whereas other less cooler had given two seedlings.
But again I have very little experience ... and a lot of
questions.
Good evening and thank you for your interest.

Sorry, I made a mistake.
Instead of " less cooler" I think: "less fresh seeds" should be better.
Good evening.

An update on my seed sowing. Has I said previously above, I sown seed from Koehres on the 1st March and today I have 3 seeds which are showing signs of germination, so it looks like Koehres have a good source of seed this year.

Hello Tam.
I'm happy for you.... And full of hope for me (my seeds of Mammillaria roemeri come from the same producer). Fingers crossed again.
Good evening.