Most difficult cactus to flower

[gerald]

Interesting points Dave.

Have you considered getting another S rauschii and see if you can get that to flower?

I only have a few plants that are 'doubles' and what I find interesting is that they almost always flower at exactly the same time as each other, even if on different shelves and therefore different microclimates.

[PeterW]

My L. principis used to flower each year, but has stopped doing so - I repotted it but it made no difference. Is still alive and growing some. I have a grafted Aztekium ritterii that has never shown any inclination to flower, although A. hintonii (own roots) and a grafted A. valdezii oblige often.

[FaeLLe]

I have a grafted Aztekium ritterii that has never shown any inclination to flower

Same here my grafted ritterii now has 30+ heads on it (albeit very tiny) but never flowers.

A. hintonii (own roots)

These flower for me without warning! I almost missed the tiny flower.

[gerald]

A. hintonii (own roots)

These flower for me without warning! I almost missed the tiny flower.

I'd love to see pics of this if possible?

For the record, my A ritteri (grafted) never fails to flower, so it is possible

[DaveW]

I grew my Aztekium hintonii from it's dust like seed when it first became available and also Geohintonia too but lost those in a bad winter. It looked as if there were no seeds in the packet therefore you have to carefully tip them out over the seed pan and tear the packet up to make sure! Only one came up and surprisingly I reared it. They grow quicker than Aztekium ritteri, which must be the slowest cactus. They seem to flower when they produce the wool and bristle like spines at the crown, but so far I never got around to photographing it in flower.

It also produces those linear woolly stripe like spots or patches on the body similar to some forms of Astrophytum ornatum.

[Cidermanrolls]

Aztekium hintonii flowers are awesome, though small. This plant is a bit of a cheat as I bought it only this winter from a seller in Nuneaton.
A. ritteri flowers are not particularly exciting. This plant is not a cheat as I've owned it for about 40 years. It is, though, probably a plant that would be frowned on today as I suspect it was habitat collected. Bought from one of the Lincolnshire nurseries in the 80s.
Both are own roots.
I hope the photos attach, my first effort with pics.
The plants I've never flowered, C senilis and P pringlei.

[DWDogwood]

Neither of my 2 Copiapoa solaris that I've own for 27 years have flowered.
Cuttings root quite readily though, so there's that.