When I looked at the flowers that you can see in the featured photo, I was a little confused. I couldn’t remember seeing a dense inflorescence like this. Pink and purple buds emerged as showy blue flowers. Quite pretty. The bush was about waist-high. The serrated oval leaves were shiny after the rain. I was sure I would have remembered seeing them before. I was very surprised later when I realized that this could only be the bharangi (Rotheca serrata). The ones I saw before had shining white petals, except for the one that lay below the overhanging stamen. That one was was dark blue. This colour of the “landing petal” attracts pollinators looking for a drink. I looked at the photo carefully. Indeed there is a darker petal, properly positioned below the stamens. And yes, the range of colours recorded for this flower includes what I saw.
There is a long history of scientific mistakes and squabbles about its name. The blue fountain bush (aka the blue glory tree) was first named Rotheca serrata by Linnaeus. It has significant variation in form and colour, and has been misidentified and renamed over the centuries. For a biologist a name is more than a name. It is a means of placing a species within the history of evolution. And that has history has been retold several times. Current thought puts it in the mint/sage family, Lamiaceae. The genus name brings together only related plants. Genetic studies, published in the closing years of the previous centuries, confirmed this of Rotheca. The genus is found in tropical regions of Asia and sub-Saharan Africa. Field studies following this reclassification are still on. So the number of species in this genus is changing today.
Bharangi is widespread in India and Sri Lanka, and as far east as Malaysia. So, I was not surprised that its roots are used in several Ayurvedic formulations. They are used to treat coughs, fevers, and several related infections. There’s a fair bit of literature on extracting its active ingredients. That’s a field of work which pays off so well sometimes that pharma companies support it. So much human knowledge and activity behind that one flower! The Family asked me a simple question, “What is it?” That has such a long answer!
Don't hold your breath 