Pollination of flowers

I have a few Astrophytum Myriostigma Tricostatum's, i have tried pollinating them with eachother and have had no success.
The flowers are little bit smaller than the usual Myriostigma, also there is not much pollen in the flower.
Has anyone got seeds from Tricostatum? any advice on it?
Also with variegated cactus? same problem, do they have to be exactly the same?
I have a Variegated Asterias and tried to pollinate with normal Asterias, still no seed!

Hi,
Yes I have had similar issues with pollination on Astrophytum cultivars. I find several reason for this. If the plants are just young they will flower without setting seed(to save energy for growth perhaps, but then flowering is a waste of energy too). It is only after a few seasons at flowering size that some plants will start to set seed. Next reason I believe is that a fair percentage of cultivars because of their hybrid origins are just infertile( like a mule), I have found up to forty percent infertility with some, especially red flower and shinshowa. This seems more common with Asterias cultivars. Sometimes you will get infertile pollen but a fertile stamen other times the opposite or plenty if pollen with an absent/mutant stamen that can't set seed. Another issue is that on the first day of flower being open the pollen is often still a bit damp and won't be available in abundance or set seed. One further issue I find can be a problem is flowers from early/late in the season or during a cold snap will abort without seedset.
Then when seed is eventually produced a large number of plants will not be true to type because they throw back to the dominant gene. Also poor germination is an issue as well. Despite all this, these problems are surmountable but the only way is via dogged perseverance.
Hope this helps clarify the issue a bit, of course these are just opinions based on personal observation and I am certainly no expert so I could be wrong.

Cryptocarpa wrote:

It is only after a few seasons at flowering size that some plants will start to set seed.

Well that would explain a lot. I have been trying in vain for the last two years to get seed set from a few young Asterias. Could this also be an issue for some Mammillaria's? I have three M. Wildii plants that started flowering last season but I still haven't been able to get seed production.

Thanks cryptocarpa that does help.
I hope to get seeds at least next flowering season, i think they have flowered the last 2 years.
Its a shame about the variegated Asterias i would love to get seed from it one day.

I have several variegated asterias and can collect seeds without any problem.

variegated asterias x variegated asterias
variegated asterias x normal asterias

Seeds collected above 2 conditions give a good germination and reasonable numbers of variegated seedlings.

If the variegation is true one, I think there is no problem to form seeds.
If the variegation comes from a hybridization stress, you can not expect the seed forming.

I took a photo, a variegated asterias with a fruit in this afternoon.

fantastic photo my friend, that nishiki asterias looks really nice

Great info everyone and yes I get very similar issues especially with the cultivars/multi-hybrids. You will probably find your tricostatum is in fact a hybrid rather than a selected cultivar. By this I mean the plant was not selected from 5000 seedlings as a tricostatum but rather produced as a result of crossing two different Myriostigma and the resulting offspring or even the F2 second generation offspring is what you have. Many F2 hybrids are sterile or produce funky flowers that are almost impossible to pollinate, the challenge for us cultivators is to produce stable, strong plants that will reproduce.

All this being said I find stubborn plants can set seed towards the end of the season, I don't know why? Also some plants will set seed when stressed.

Thanks everyone for your help, i will keep trying hopefully i will get something.

Also nice Variegated Asterias Hanazono