Plant ID / Namibia / Namib desert / Sesriem

Hello,

Here is a plant seen in Namibia / Namib National Park, near Sossusvlei in the rainy season (end of november).
The flowers are white and the stems red.
It's around 50 cm high.
I have been thinking of the Prenia sp but I don't see the green fat leaves I have seen on some images.
So if someone has an idea ...
Thank you
Cheers

 

Do you have a larger image?

 

Thank you Daniel for your answer.
Here is a larger def of this plant (772 Ko / 300 dpp)

 

Looks like a Mesembryanthemum sp.

 

Yes, a Mesembryanthemum in the narrow sense as currently recognised, a group of about 15 annuals from southern Africa, several of them widely naturalised in other semi-arid regions around the world, e.g. M. crystallinum.

 

Thank you Tony and Thank you Lila
Cheers