What is Seed Pen ? 

The Pens That Not Only Reduce Plastic Waste But Also Have Seeds That Grow into Trees!. its made up of recycled paper 

These paper pens, a great alternative to plastic ballpoint pens, don’t just address the plastic menace but also contain seeds that can grow into trees.  

Once a pen has been used up, it can be just be planted into the soil. The seed will sprout from the bottom of the pen.