GOD'S WORD® Translation
It's like a mustard seed planted in the ground. The mustard seed is one of the smallest seeds on earth.

American Standard Version
It is like a grain of mustard seed, which, when it is sown upon the earth, though it be less than all the seeds that are upon the earth,

Berean Study Bible
It is like a mustard seed, which is the smallest of all seeds sown upon the earth.

Douay-Rheims Bible
It is as a grain of mustard seed: which when it is sown in the earth, is less than all the seeds that are in the earth:

English Revised Version
It is like a grain of mustard seed, which, when it is sown upon the earth, though it be less than all the seeds that are upon the earth,

King James Bible
It is like a grain of mustard seed, which, when it is sown in the earth, is less than all the seeds that be in the earth:

World English Bible
It's like a grain of mustard seed, which, when it is sown in the earth, though it is less than all the seeds that are on the earth,

Young's Literal Translation
As a grain of mustard, which, whenever it may be sown on the earth, is less than any of the seeds that are on the earth;

Mark 4:31 Additional Translations ...