Thorned roots, also referred to as spiked roots are an obstacle in two rooms of Sector 1 / Biosphere. They are large, spiky, fuchsia-colored roots that stretch across a slope, or grow to its sides. Samus automatically slides down slopes, and must move out of the path of the roots or jump over them to avoid taking severe damage, losing at least 23 energy units. The first room with a slope and thorned roots is a "Waver-infested corridor", while the second is at the entrance to the "rainforest".
- ^ Metroid: Other M Premiere Edition page 58: "Dash down the next long hallway and destroy the Wavers as you go. As the hall turns right, it also begins to slope down. Slide down the slope, leaping over thorned roots, until you reach the end of the long hall."
- ^ Page 55: "Exit the crooked corridor and find a long, sloping walkway full of huge spiked roots and a few pesky Grippers. Edge toward the slope and begin your eventual slide down the walkway. The decline is too steep to walk back up, so once you begin your descent, you'll be unable to navigate in any direction other than down. Leap over the spiked roots as you go until you reach the bottom of the slope."