Euphorbia species
It is extraordinary how many Euphorbia there are and how much 
they differ from each other.  The only way to know they are related 
is by the  flowers.

Here is a photo of the tiny ground cover.  The leaves are very small  
in dry weather and  much larger(in  comparison) in easy conditions.  
I added my finger tip for scale.

   

It was only recently that I found out that this old favorite ground 
cover  was in fact an Euphorbia!

Never forget that the milky sap or latex of  the Euphorbia plant
is highly toxic.  Especially in the eyes.  There is one very fierce 
large tree size Euphorbia in the northern parts of South Africa 
where it is dangerous  in habitat where those large plants grow
to walk downwind when they are in bloom.  Your eyes will start 
burning and you better cover the eyes and nose with a  piece of 
cloth quickly.  
Surprisingly the bees and butterflies love the flowers !
   
   

   
There are animals - even domestic cattle - that eat some of the 
Euphorbia species.  This is life saving for the animals in 
Namaqualand and the Karoo.   
I would like an assortment Euphorbia  between the aloe 
plants but most of the pretty or odd ones are rather difficult 
plants out of their habitat.