Questions about Echinopsis blooms

[PresidentKang]

Well, it appears I spoke to soon in my last post, when I said I was disappointed about my E. subdenudata didn't bloom this year...

It did end up putting out one bloom, which opened early this morning. I'm a bit bummed so far, as it hasn't fully opened, and it's not as showy and ornate as a lot of the blooms I see online for this variety. Does anyone know what might have caused this? Any chance it will be fully open later today, or is this it? And, what to do with that massive stalk once the bloom is done? Should I cut it, or let it shrivel up and fall off naturally? It doesn't fit under my grow lights!

On the other hand, this makes three blooms (2 different plants) in my first spring after trying a cold, fully dark winter for most of my plants. So I'm happy my experiment worked!

[7george]

I think this plant should open its flowers at night. Maybe you missed the time it was fully opened? Check next buttons (if any) in the evening, ~ 8 - 9 pm.

[hegar]

Although I do not have an Echinopsis subdenudata, I do have a big clump of Echinopsis eyriesii, another night-flowering cactus, which does look similar to your plant. I used to stay up until midnight, when the flowers would fully open and take pictures in the dark, with oftentimes mediocre success, when judged by the image quality.
Then I found out, that until at least 09:00 h the next morning the blossoms remained fully open. I also noticed, that the flower color was not solidly white, but some pink was present in the outer petals.
My plant does flower only one night per blossom, but does so repeatedly until fall. I hope, that I did help you a bit with my writing.

Harald

[greenknight]

As for the long floral tube - it will shrivel and fall over within a few days, only the ovary at the bottom will stay upright and develop into a fruit (if it pollinated). Whether to trim off the remains of the flower after that is up to you, makes no difference.

[ElieEstephane]

If it was pollinated, do not trim the flower until fully dry! Pollen could still be stransferred down the stigma. Trimming the flower too early will result in reduced number of seeds or seeds that are not viable

[DaveW]

The flowers are nocturnal and usually stay open part of the next day. It can depend on heat though since they will whither the next day if it is warm, particularly in a warm climate, but if cool and cloudy when flowering may stay open a couple of days. Also flowers that are pollinated die quicker than those that are not having served their reproductive purpose, therefore then are just a drain on the plants resources to keep open loosing water in hot climates, so those resources are then switched to forming fruits. If unpollinated they will stay open as long as possible in the hopes they will get pollinated.

[PresidentKang]

Thanks for all the replies, everyone!

These pics were taken at about 3:00am the night that it bloomed, so I guess it just didn't open all the way. The flower is closed now and has flopped over on the stem. I don't think it was pollinated, but I'll wait a few days just to be sure.

I learn something new every time I come to this site, thanks again for all of your help!