Another mystery plant...multi-stemmed

[MAJ]

Anyone have any clue what this is? Lots of about 1-2cm diameter stems with small leaves. Thinned it out, has half dead in the drought.

 

[Marck]

These are the leaves and old flowers of Van Houtte's Bridal Wreath Spiraea (Spiraea x vanhouttei) in the Rose family (Rosaceae).
Spiraea x vanhouttei is a hybrid of the Asian species Spiraea trilobata × Spiraea cantoniensis. It was first bred in France in 1862.