Preference is for large stumps where there has been some heartwood softening by the fungus Phaeolus schweinitzii.
Lignans, such as 6“ - bromo - isoarboreol, 4-hydroxysesamin, 4,8-dihydroxysesamin, 1,4-dihydroxysesamin (gummadiol), 2-piperonyl-3-hydroxymethyl-4-(α-hydroxy-3,4-methylenedioxybenzyl)-4-hydroxytetrahydrofuran and the 4-O-glucoside of 4-epigummadiol, can be isolated from the heartwood of Gmelina arborea.
Lignum vitae, heartwood of tree species of the genus Guaiacum, native to subtropical and tropical regions of the Americas
Kannada people in India make a wooden glass (tumbler) from the heartwood of this herb (tree) and its aqueous solution is used to cure diabetes.
Valoneic acid dilactone, flavogallonic acid dilactone, gallagyldilactone, ellagic acid and gallic acid are hydrolysable tannins that can be isolated from the heartwood of S.
Old trees are commonly attacked by various fungal disease and decay species, notably Heterobasidion annosum and Armillaria species, which rot the heartwood and eventually leave the tree liable to windthrow, and Rhizina undulata, which may kill groups of trees following minor grass fires that activate growth of the Rhizina spores.