India, March 14 -- This portion of the Vasant Vihar pave is littered with yellow flowers and pink flowers. It is night at the moment, but the flowers are shining brightly in the dark, perhaps helped by the ample street lighting. The pink flowers certainly are bougainvillaeas, but the yellow ones? This isn't yet the season for summertime yellow Amaltas.

These are actually the blossoms of the so-called Tree of Gold, the Caribbean Trumpet. Brought in Delhi in the 1970s, it is in bloom across the city. In Jangpura, a showy crop of yellow trumpets is currently overlooking a lush cascade of pink bougainvillaeas. From a distance, the scene looks as if two friends were throwing gulal at each other.

Another night, in Gulmohar Park, a brown dog is ...