Lithocarpus kalkmanii

Lithocarpus kalkmanii is a tree in the beech family Fagaceae. This species is named for the Dutch botanist Cornelis Kalkman.

Description
Lithocarpus kalkmanii grows as a tree up to 30 m tall with a trunk diameter of up to 60 cm. The brownish or greyish bark is cracked or lenticellate. Its coriaceous leaves are tomentose and measure up to 15.5 cm long. The dark brown acorns are roundish and measure up to 6 cm across. This species produces fruits with an 'enclosed receptacle' morphology, where the seed becomes embedded in the basal tissue of the fruit as it develops. This basal material becomes woody, granular and hard and replaces the outer wall of the ovary as the mechanically protective tissue for the seed.

Classification
This species probably belongs to the subgenus Eulithocarpus, based on Camus' infrageneric classification system, because of its 'ER' fruit morphology and the few widely spaced concentric lamellae on the cupule.

Distribution and habitat
Lithocarpus kalkmanii is endemic to Borneo where it is known only from Sabah. Its habitat is mixed dipterocarp to montane forests from 1000 m to 1500 m elevation.