A new (to me) word: inosculation

Inosculation is a natural phenomenon where the trunks, branches, or roots of two trees grow together and fuse. It acts like a natural graft, letting the plants share water and food. The name comes from a Latin word meaning "to kiss". 

Of course as poets inosculation may be seen as a metaphor of enduring love. 

Inosculation [excerpt]

by Emma Gousset 

if you were to ask me about us

I’d tell you about inosculation

the natural phenomenon between two trees

growing together

derived from latin roots

in + ōsculārī

“to kiss into/inward/against”

Read the entire poem

https://www.salvationsouth.com/inosculation-emma-gousset-queer-nature-poetry/

Baucis and Philemon

[per Wikipedia] a story of enduring love

The story of Baucis and Philemon is a classic Greek myth about an elderly, poor couple who show great kindness, kindness, and love. Zeus and Hermes disguised themselves as poor travelers and walked through a town in Phrygia. 

As a reward for their kindness the couple made this request: when they grew very old, they asked the gods to let them die at the exact same time so neither would live alone. Zeus turned them into two trees—an oak and a linden—growing from one single trunk. 

Read about The Myth of Baucis and Philemon

https://madelinemiller.com/myth-of-the-week-baucis-and-philemon/