Which of these is an ingredient to the Polyjuice Potion?

Ingredients

• Lacewing flies(Stewed for 21 days)
• Leeches
• Powdered Bicorn Corn
• Knotgrass
• Fluxweed
• Shredded Boomslang skin
• A hair from the person you wish to become

I think these are correct, I checked a few sites and they were all similar.