Once there was an Asura (demon) named Analasura. He was so terrible that the earth would tremble by his voice and his eyes used to emit fire. So everybody was very scared of him.
Even the Gods were terrified. So all the gods prayed to Ganesha so he would rescue them from the clutches of Analasura. Ganesha became into a child and assured all the Gods that they would be saved from Analasura.
Ganesha started “Sarvkasha” war. Analasura’s powerful eyes oozess out fireballs and destroyed surroundings of Ganesha. At the end Analasura tried to gulp Ganesha but Ganesha himself showed his “virat “ roop and gulp Analasura to destroy but due to increased heat in body Ganesha could not even lie down. He was restless.
He applied sandal paste all over the body even though the body’s heat was unbearable. At this moment all Gods decided to make a foundation of the moon on his head and Ganesha is also known as “Bhalachandra. Lord Vishnu gave his lotus therefore Ganesha is also known as “Padmapani”. Lord Shankara removed a cobra from his neck and tied it to Ganesha’s hip. Lord Varuna, Rain God showered plenty of water, heat was not subsided. Some of sages who came there with bunch of 21 Durvas and put on his head and a miracle happened. Ganesha became all right.
Ganesha uttered that most of the Gods tried to help but only ‘Durva’ a simple grass made my agony into normal. With this he announced that whoever with devotion offer me Durva would be pious and get Punya.
Secondly it is said that there was a most beautiful Apsara who devotionally loved and prayed to get married with Ganesha. Ganesha also used to like her. But Parvati, Ghanesha’s mother cursed Apsara to become a simple grass form on the earth where nobody would look at her. But Durva begged for pardon and asked for ushaap.
Parvati forgave her and told her that even though she is in the grass form she would be adored by Ganesha.