What type of structure forms when a speleothem on the ceiling of a cavern meets with a speleothem on the floor of a cavern?

Stalactite and stalagmite, elongated forms of various minerals deposited from solution by slowly dripping water. A stalactite hangs like an icicle from the ceiling or sides of a cavern. A stalagmite appears like an inverted stalactite, rising from the floor of a cavern.

A column