A hemiepiphyte is a plant which begins its life as an epiphyte

Epiphyte

An epiphyte is a plant that grows upon another plant non-parasitically or sometimes upon some other object , derives its moisture and nutrients from the air and rain and sometimes from debris accumulating around it, and is found in the temperate zone and in the...

 but which later grows roots down into the ground. The seeds of hemiepiphytes germinate in the canopy and initially live epiphytically. They send roots downward, and these roots eventually make contact with the ground.

Strangler fig

Strangler Fig

Strangler fig is the common name for a number of tropical and subtropical plant species, including some banyans and unrelated vines, including among many other species:* Ficus aurea, also known as the Florida Strangler Fig...

s are hemiepiphytic – they begin life as epiphytes but after making contact with the ground they encircle their host tree and "strangle" it. This usually results in the death of the host tree, either through girdling

Girdling

Girdling, also called ring barking or ring-barking, is the complete removal of a strip of bark from around the entire circumference of either a branch or trunk of a woody plant. Girdling results in the death of wood tissues beyond the damage...

or through competition for light.