The word Kowhai is the Maori name for yellow. The Kowhai flowers in spring on bare branches, and James Cowan told of the Maori explanation of this in an article in the New Zealand Railways Magazine 1928. I have written a condensed version below:
On the shore of a lake in the long ago times sat a young Maori man and maiden. The man loved the maiden and asked to marry her, but she laughed and required him to carry out some great deed before she would become his wife. The lover was an Ariki (chieftain) and tohunga. Above them was a tree bare of both of flowers and leaf in the cold of early spring. The young man recited a chant which caused the tree to burst forth into a blaze of golden blossom. Ever since then the Kowhai has flowered on leafless branches as a sign and a reminder of his love.