Playing dead and well-camouflaged: more weird sci-fi plants

Euphorbia cylindrifolia is originally from Madagascar and if you grow it in full sun, the leaves are brown and look dead although if kept outside the tropics, the leaves go greener. If they are grown from seed, the develop a large underground tuber over time but this one will not because it was grown from a stem cutting.
This is the only time I have seen a plant with brownish flowers, here's a closeup:

Euphorbia can be difficult to grow because they like lots of sun, heat and regular water but will rot if the soil around their roots remains damp so they need to be grown in clay pots with coarse gravel that drains very quickly. I love euphorbia but I killed all of mine rather quickly the first time I attempted growing them a couple of years ago but I am trying again. Hopefully I have learned my lessons and I keep the new bunch I got alive this time.

On Saturday, our local succulent society is having its autumn show and I will be allowed to go in before it opens to take photos. I'll be sure to take lots of pictures of the plants entered into the competitions for everyone to see. After the nasty plumbing surprise, I'm going to have to restrain myself from buying too much although I keep telling myself that these plants are an investment. It is a long-term goal of mine to start growing collectable succulents for sale and trade at shows like this one