Hibiscus.

Hot and tiring day at the charity shop - "Vintage Weekend".  I had intended to blip some of the stuff, but in the end shot out at 4:30 quite keen to get home!  So here's my trusty hibiscus, always happy to bloom, in spite of neglect and very little watering. 

I have another one, which has grown much taller, but never blooms. Does anyone know why that is?