yes it does look like one but macrocarpa is the only one I recognise.

Maybe yes macrocarpa. Take a look at Carissa macrocarpa 'Nana Compacta' aka Carissa macrocarpa 'Tuttlei' or C.m. 'Tuttle'.

Thank you both!

I only wonder becaus I see no thorns, as 'Tuttlei' seems to have. I am impressed with the performance of the plant in Palm Springs.

Maybe it is C.M. âÂÂBoxwood BeautyâÂÂ, which is compact and nearly thornless. Or another, similar, cultivar.

Yes, thank you, likely 'Boxwood Beauty'.