heartwood timber BrE
heartwood lumber AmE

The houses were built of Florida pine, using 8x8 heartwood timbers for the foundation and frame.

Also, it usually does not attack heartwood timbers.

Several species are used for timber, producing a hard, dark heartwood timber similar to ebony.

Many of the strongly termite-resistant tree species have heartwood timber that is extremely dense (such as Eucalyptus camaldulensis) due to accretion of these resins.

Lissocarpa species share various characters with other members of Ebenaceae, e.g., the black color of roots and bark, extrafloral nectaries on abaxial leaf surfaces, a persistent calyx, unisexual flowers, biovulate carpels with pendulous ovules, and a similar wood anatomy producing a hard, dark heartwood timber similar to ebony.