How could trees in an environment with 23% Oxygen (The atmosphere is identical to earth in all other respects.) grow bark with Starlite-like qualities?
Starlite is a material claimed to be able to withstand and insulate from extreme heat. It was invented by British amateur chemist and hairdresser Maurice Ward during the 1970s and 1980s, and received significant publicity after coverage of the material aired in 1990 on the BBC science and technology show Tomorrow's World. The name Starlite was coined by Ward's granddaughter Kimberly Ward, who died in 2011, revealed the composition of Starlite only to his closest relatives. The material is believed to be a type of intumescent material (a material that swells with heat exposure) and products with roughly similar properties are commercially available. The American company Thermashield, LLC claims to have acquired the rights to Starlite and replicated it.
Could it absorb the materials required from the ground?
Link to a video on Starlite --> https://www.youtube.com/watch?v=10C5oQiUU_U