Guess the flower!

[Cactus Kid]

I only ever get one or two flowers on this each year. Love the unusual colour.

[DaveW]

Pterocactus?

[MikeT]

Pterocactus?

tuberosus

[DaveW]

Regarding identification, not sure it's P. tuberosus although flower colour does vary to some extent and some can have flowers with either red or yellow stigma lobes on different plants. P. tuberosus does have red and yellow stigma'd forms.

[ralphrmartin]

I had a Pterocactus whose flowers were exactly the same dark brown shade as the stems. I almost missed the flower!

[MikeT]

Does look very like the flowers on my tuberosus, but I was also going by what's visible of the stems, and that tuberosus is relatively common in collections. Could of course be entirely wrong ... wouldn't be the first (or, no doubt, last) time

[Cactus Kid]

The answer!

[MikeT]

The label says 'kuntzii' (kuntzei) - so tuberosus it is then...

[KathyM]

I love the weird flower colour too. I have had my Pterocactus tuberosus plant for years and never once had a flower. I have read that the trick to getting them to flower is to remove the stems each year so I'm going to give that a go and see if I get any flowers next year.

[DaveW]

I have done both Kathy. Pruning down to a couple of stems will promote almost immediate flowering since tuberosus usually looses most of their stems in winter in habitat I believe. However as an experiment I left all the stems on for a few years and got no flowers for a couple of year's, but after it grew even more top growth it eventually started flowering again. Also I think they like a cool winter rest and mine go down to freezing or just below every year. At the moment it is budding up, but looks like a birds nest of stems.

This was it when I pruned it, but the tuber in the pot is as big as a golf ball which carries it through the winter without needing a lot of top growth.

Pterocactus tuberosus (syn. kunzei)

I find the other species of Pterocactus do not always loose their top growth like tuberosus over winter, but the stem ends do tend to dry up and you can snap the dead parts off. They are really not show plants since they are terminal flowering so that stem looses its growing point leaving a crater where the flower was and then has to sprout from below.

Note the crater at the end of the stem where the previous years flower was in the picture below and how the new flower is sprouting from a new joint just below since the original stem growing point is lost, therefore the stem cannot grow any further from where the previous years flower was.

Pteoocactus HPT-791

I like Pterocactus and have around a dozen, but they are tatty looking and not really show bench plants, or is that just my poor growing, but at least they do flower every year.

Pterocactus reticulatus