It is indeed a delight to watch Athirani blooms when they begin flowering during Onam season (August – September). It lasts until around November. Being a type of herbaceous plant with beautiful pink flowers, it spreads on vast stretches of fields.
The common name has lots of ambiguity. In many parts of Kerala, it has slightly different local names. In some places, it is known by the name Cherukadali, while in other areas, the name is Kunjathirani, and so on.
Also, at first glance, it resembles Kadali – a native shrub once common in Kerala. But now, unfortunately, it is very rare, or maybe even nowhere to be found. The older generation can remember Kadali with a bit of nostalgia only. Kadali Poovu was an essential item for making Pookkalam during Onam Festival.
As far as I could find, its botanical name is Osbeckia parvifolia. It belongs to the family Melastomaceae. In English, it is called Small Leaf Osbeckia. However, in some references, it shows four petals. It causes confusion as these flowers (in the photos) mostly have five petals.
It is almost similar to Wall Osbeckia (O. muralis), both grows very well on field walls.
So the id is not confirmed. If somebody reading this has more info, feel free to state it in the comments.
Unlike the Malabar Melastoma which is an erect shrub, Athirani is a loose herb with prostrate stems. It spreads like a creeper and barely reaches more than 40 cm above the ground.
The flower is pink and 2 – 3 cm wide, which is much smaller than Kadali (M. malabathricum). Usually, it has five or four petals. They bloom each morning and wither by evening. The flowering season is normally from September to November.
The leaves are small and dark green, covered with short hairs. The size is around 3 cm.