Haustorium

For example, in mistletoe or members of the broomrape family, the structure penetrates the host's tissue and draws nutrients from it.

In mycology, it refers to the appendage or portion of a parasitic fungus (the hyphal tip), which performs a similar function.

The etymology of the name corresponds to the Latin word haustor meaning the one who draws, drains or drinks,[2][3] and refers to the action performed by the outgrowth.

Generally, on penetration, the fungus increases the surface area in contact with host plasma membrane releasing enzymes that break up the cell walls, enabling greater potential movement of organic carbon from host to fungus.

The host supplies organic carbon to the fungus, and the metabolic activity within the complex is considerably greater than outside.

They keep their leaf stomata open night and day which sets up a moisture gradient between mistletoe and host.