This makes the rock crack along its weakest point.

The plant relies on seeps of water coming from the rock cracks.

It is the result of ground water freezing in rock cracks in the ceiling.

He reached up with his free hand, thrust it into the rock crack above the other, and made another jam-hold.

Individuals grow on canyon rims and in rock cracks.

I don't propose to stand around here gaping until a rock cracks my skull.

The plant can be found in rock cracks.

It can often be found in rock cracks on steep slopes and cliff faces.

It sometimes grows in rock cracks on steep cliffs.

There was a tiny rasping sound as the toe of one boot moved in the rock crack.