The ‘Ōhi‘a lehua legend as explained from this excerpt:  "In Hawaiian mythology, ‘Ōhi‘a and Lehua were young lovers. The volcano goddess Pele fell in love with the handsome ‘Ōhi‘a, but he turned down her advances. In a fit of jealousy, Pele transformed ‘Ōhi‘a into a tree. Lehua was devastated. Out of pity, other gods turned her into a flower on the ‘ōhi‘a tree. Or, some say Pele felt remorseful but was unable to reverse the change, so she turned Lehua into a flower herself. When a lehua flower is picked, the rain will come representing the separated lovers’ tears. " 

Source:https://dlnr.hawaii.gov/hisc/files/2018/10/Rapid-Ohia-Death-Poster.pdf 

This episode is also available as a blog post: http://hawaiinaturelove.com/2019/10/25/the-lovers/