Cavernous Tigerlily

Almost exactly what it says on the tin.
When the ecosystem was closed off from the surface, many species of plants used bioluminescence as a means to attract insects for pollination. However, many of these are going extinct, especially to the east, where a new entrance allows the old insects to fly off and new ones to devour them.
For all we know, this could be the last of its kind.
One in a million indeed.

Rendered in Photoshop