carbonous

The genus Thamnomyces has a slender stem, entirely carbonous.

They have a solid carbonous interior with the perithecia imbedded near the surface.

In the old days all similar carbonous fungi were called Sphaeria.

The usual Xylaria has a white, sterile, central portion known as the stroma, bearing a carbonous crust.

The perithecia are generally imbedded in the outer portion of the stroma, the mouths opening through the carbonous crust.