Which plant's part is this?
This is a bit hard to say exactly, since there is a number of possibilities. We can be pretty sure that these sample is from a Cypress, belonging to the family of Cupressaceae, but which subfamily or species this is exactly, can't be identified here. Therefore a wider image would be necessary, but since this is a potted plant, even this might not be enough, as a lot of these plants are used in gardening.