This question is dumb but it's obviously going to be popular since people like dumb things, and my answer was requested so I might as well it quickly and my answer is not going to be popular but that's fine.

• Obviously, no plants can't scream, and it is obvious enough why.
• There's no such thing as “the mandrake plant”. Mandrake plants are individuals, and there are up to 5 known different species.
• Harry Potter is fiction and fantasy is not a reliable source of information.
• J K Rowling just reused an old Medieval urban legend that mandrake plants scream when you pull them up and the scream can kill you, so you should tie the plant to a dog and have the dog pull it up. Some people actually did use a dog, and the dog was of course unharmed (although eating Mandrake plants is an entirely different matter because they are poisonous), so people knew it was false, and the roots scantly resemble a person, so they knew that was also false, but people love “a good story” more than “boring reality”, so people make things up.

The plant that can kill and cure

Of course not. But on a warm day you CAN hear corn squeaking. Really.

HOWEVER: Plants emit ultrasonic 'scream' when they are hurt, researchers find