The wall faces SW.

Third plant is the mother of the 5 seedlings in the middle. She is flowering for the third time (2 scars visible from previous years).

The Beaucarnea on the right recently finished flowering for the first time and is due to branch soon.

Hanging in the wall top right are two dry inflorescences from an aloe tree which lives down below, definitely the worse for wear now 5-6 years later. This plant.

Wow, I never have had a Beaucarnea bloom. Amazing! It must love the weather there.
Did you grow those young Pachy lamerai from your own seed? My P. geayi and lamerai both died after about 5 years of growing. I suspect the very high heat, but am not sure. Maybe I watered when I shouldn't have.
I have Aloe marlothi in the ground here in afternoon shade. Grows well but no flowers. However, I don't mind that. At least it isn't all burned from sun and/or heat exposure like many of my plants. Here is an example: Obregonia denegrii

Ooh yeah I see, not pretty. Is that reversible or is that a goner?

I think the branching on the Beaucarneas is kind of variable as to when it occurs. Some of that (maybe most of it) would be genetic. I'm not really spoiling my plant. But yes, that's a pretty small flowering size, and it portends good things (branching to come in the near future).

Those 5 young Pachypodiums are 1-2 year old seedlings from the mother plant at their left. I would imagine they would have trouble with your insane heat. They really like the water in summer when they are leafy, very un-succulent-like behavior at that time, but you know that already, I'm sure. Here in our mild climate I water the active Pachys twice a week, but our summer high to date is 76°F and we don't spend hardly any time over 90°F.

The Aloe marlothii & hybrids here seem to be pretty tough plants overall. Good with drought too. Maybe yours needs to get bigger to flower? Some of these tree aloes are late bloomers for no particular reason that I can tell. I'm still waiting on a ferox about the same size to bloom, years after putting it into the ground.

The Obregonia is a goner. The most likely reason is it got watered when it was 118º when I was away. My husband is a wonderful help but I can not expect him to know plants! I told him to water when I was gone and he did. Of course, I was not taking into account the extreme temps we are having. Finally we are getting a stretch below 110º during the day. But still the heat is unbelievable!

I can not find the post where you gave me the names of 2 good fatter Euphorbias. Can you please tell me again?

I always love any info on growing you have. I may know or I may not! Even if I think I know, I like reinforcement! I did not realize Pachys like water in the summer. I have only one left, a P. saundersii. It did not look happy outside. The leaves were all curled up and as soon as I brought it in the house, they reopened.

My problem is there is not a good place inside with enough sun for plants. Ugh!

I hope you are right on the Aloe marlothii. It is so hard here to give enough sun but not burn plants. I have an Aloe 'Hercules' in the ground that I planted at about 3' maybe 4 years ago. I has not bloomed yet either. Yes, I think I just need to be more patient!

Try watering your Pachypodium more often this time of year. It sounds like you may have saved it just by bringing it in from the heat. They like as much light as you can possibly provide (esp. indoors). For you of course the issue is balancing the light (good) with the casserole effect (bad) this time of year. This year I moved my P. saundersiis out from under overhead protection for the first time and they responded by putting out a huge growth spurt.

If your Pachypodium is subject to serious heat and really low humidity, you might water every day in summer. Never less than twice a week while it's leafy and temps are warm, given a pot matching the size of the plant. As long as your mix has enough rock (50% pumice or equivalent) and the plant is in active growth, there should be no problem with lots of summer water. It's a bit how you might treat an Adenium. I think I probably still underwater both.

I hear you on insufficient light indoors. I have completely taken over all the sunny areas available here and that's just for my smallest seedlings. It's a bummer for you because of the heat.

The fat Euphorbias I like include polygona (red flowers, sometimes grey-blue stems), horrida (similar but green flowers), and anoplia (stripes on green stems, red flowers), these 3 closely related. Also fruticosa, and for fatness you can't beat obesa. Those would be marginal in your zone 9b winters and I'm not sure how much summer sun they can take there, but here on our balcony the first few plants thrive in all-day sun. I grow them dry (mix goes dry every time) and the sun helps a lot with that.