https://wccftech.com/how-to-break-past-firegleam-in-horizon-forbidden-west/

Sooner or later, Aloy will come across strange barnacle walls in Horizon Forbidden West. These orange flowery walls routinely block paths forward. Like most roadblocks that bar Aloy's progress, these lead to side paths and optional areas filled with loot and materials.

When Aloy first stumbles upon these red walls, they pop up as an anomalous growth when scanning them with her Focus. It isn't until Aloy acquires the right Special Gear to blast them out of the way that their true form is revealed as Firegleam. With the right upgrade, Aloy's Spear can set them ablaze. Be careful, though! These explode violently and can cause damage to Aloy if you don't get out of the way fast enough.