Crossandra Infundibuliformis / Kanakambaram flower / Firecracker flower
Info from Wikipedia:- The plants are native to Southern India, Malaysia and Sri Lanka. It is usually grown in containers but can be attractive in beds as well. Flower colours range from the common orange to salmon-orange or apricot, coral to red, yellow and even turquoise. They are evergreen and bloom continuously almost throughout the year.The flowers are unusually shaped with 3 to 5 asymmetrical petals. They grow from four-sided stalked spikes. They have a tube like ¾ inch stalk which makes it easier to string them for a garland. These tiny flowers are often strung together into strands, sometimes along with white jasmine flowers and therefore in great demand for making garlands which are offered to temple deities or used to adorn women’s hair. The flowers have no perfume but stay fresh for several days on the bush.
The main reason they are known as “Firecrackers” is because their seed pods, which are found after the flower has dried up, tend to “explode” when near high humidity or rainfall. The “explosion” releases the seeds onto the ground, thereby creating new seedlings.