In his book, Sita: An Illustrated Retelling of the Ramayana, Mr. Devdutt Pattanaik talks about an interesting event during the exile period of the śrī Rāma, Devī Sītā & Lakṣmaṇa, where Devī Sītā curses four entities (a river, a Brahmin, the Tulasī Plant and the Cow) and blesses the Banyan Tree with a boon.
Here's the Screenshot of the described incident in the writers' book.
To corroborate this described incident, I read about the Phalgu River on Wikipedia and the same above incident is described as follows, thus adding some slightest possible credibility perhaps (although the original reference for this story in the Wikipedia too is not a strong one itself), anyway, here goes:-
There is reference to the city of Gaya and the Phalgu in the Ramayana in which it says that Sita had cursed the Phalgu River. There is an interesting story and the purana states that on account of this curse, the Phalgu lost its water, and the river is simply a vast stretch of sand dunes. According to history, in the absence of Rama, his wife Sita offered pinda on its banks to Dasharatha father of Rama.1
The story goes that Rama, along with his brothers and Sita, came to Gaya to perform the sacred rites for his father, Dasaratha. When the brothers were bathing in the river, Sita was sitting on the banks, playing with the sand. Suddenly, Dasaratha appeared out of the sand, and asked for the Pindam, saying he was hungry. Sita asked him to wait till his sons returned, so that she could give him the traditional Pindam of rice and til. He refused to wait, asking her to give him pindams made of the sand in her hand.
Having no other option, she gave him the Pindam he desired with five witnesses – the Akshaya Vatam, the Falguni River, a cow, a Tulsi plant and a Brahmin. Soon, Rama returned and started the rituals. In those days apparently, the ancestors would arrive in person to collect their share, and when Dasaratha did not appear, they wondered why. Sita then told them what had happened, but Rama could not believe that his father would accept pindams made of sand. Sita now mentioned her witnesses, and asked them to tell Rama the truth.
Among the five, only the Akshaya Vatam took her side and told the truth, while the others lied, trying to take Rama’s side. In her anger, Sita cursed all of them thus: the Falguni river henceforth would have no water at Gaya; the Cow would no longer be worshipped from the front as all others are- only its backside would be worshipped; there would be no more Tulsi plants at Gaya and the Gaya Brahmins would never be satisfied, they would always be hungry and crave more and more. She then blessed the Akshaya Vatam saying that all who came to Gaya would perform the Pinda pradaanam at the Akshaya Vatam too.
In another a slightly different version, which I recently heard on a Religious Indian TV Channel and have read it on several internet forums, instead of cursing the tulasī plant, the Ketakī flower is cursed by Devī Sītā (i.e., Ketakī - to not being used to Worship any deity or in some stories only not to be used for Lord Shiva ' worship).
So, tl;dr : What might be the scriptural or maybe even any local/indigenous folklore based traditions' references for the above Story(s) ?
I'd also like to know (if possible) the validity of these curses and boons vis-a-vis how exactly they are presently manifest in Gaya, the present day visible manifestations of the Curses? The river is dried up definitely in the cursed portion. But,
- How are the Brahmins hungry always in Gaya?
- We really don't worship cows from front (do authoritative scriptures say so) ?
- The Tulasí plant really doesn't grow in that particular area or Gaya?