Nurse Plant:
!["Nurse plant pinon pine for Joshua trees](http://desertgazette.com/blog/wp-content/uploads/2016/02/599-nurse-plant.jpg)
This pinon pine tree is nurse plant for a tiny forest of tiny Joshua trees.
Nurse plants are plants that help other plant species grow by providing shelter, a safe microhabitat for seed germination and seedling growth beneath their canopy.