S. pumila is one of the very tiny species which hybridizers have tried to use in miniaturizing hybrids. Unfortunately, this hasn’t worked well, and there are only a few cultivars available incorporating the genes of these micro-miniature streps. One of these is S. ‘Blue Streaker’, which involves S. cyanandrus and S. erubescens, species similar to S. pumila.
Part of the problem is cultural, as the tiny species are difficult to grow well, and this characteristic has been passed on to their hybrids.
Another plant of the species may be seen here.