Mountain ebony in blossom

The mountain ebony (Diospyros montana, Ebenaceae) is currently in blossom at Dokmai Garden, Chiang Mai.

The stout female flowers have four reflexed lobes.

Size and shape of the leaves may vary significantly even within a tree, but a very distinctive characteristic of this species is that some leaves have heart-shaped leaf bases.

Mountain ebony may have thorns, but that is sometimes not very pronounced. The yellowish fruits are rounded with reflexed lobes. If you cut one of the black seeds you will see a homogenous interior, while many other ebonies have in-growths of the seed coat, making it look marbled (ruminate endosperm). The fruits are a classic source of wormicide and were also used to kill fish. Cut fruits oxidize to an inky black and the fruits have been used to dye textiles and fishing nets.

The tree does not grow very tall (15 m) but the wood is hard and beautiful. Another trade name is ‘Bombay ebony’. Its native range includes India, Southeast Asia and Australia. It was originally described by William Roxburgh in the first volume of his famous and illustrated book ‘Plants of the Coast of Coromandel’ from 1795.

Identifying Thailand’s more than 60 ebony species may be quite a challenge. I use Gardner’s ‘A field guide to the forest trees of northern Thailand‘ as well as Flora of Thailand (vol. 2:281-392, 1981). The vernacular Thai names are not specific, so ‘ma kluea’ or ‘ma khuea’ and its variations may refer to any ebony or even eggplant.

The vernacular English name ‘ebony’ is based on Latin ‘hebenus’, which according to Mabberley’s Plant Book originally referred to Dalbergia melanoxylon, the African blackwood of the bean family (Fabaceae). In the book ‘Roman wood-working’ it is argued that ‘hebenus’ may have been a Roman vernacular name for many tropical hardwoods. ‘Ebony’ was later associated with what we today call Diospyros ebenum from India. Linnaeus’ scientific name Ebenus is a genus of legumes, while Kuntze used the same name for the ebony genus which Linnaeus had already named Diospyros (meaning ‘fruit of the gods’, a name he used for ‘date plum’ Diospyros lotus from China). If there are two names for the same genus or species, then the oldest name (Diospyros) has priority, and the younger (Ebenus) is illegitimate. Logically the ebony family should have been named ‘Diospyraceae’, but ‘Ebenaceae’ was already so widely used when the relationship between date plum and ebony became clear, that changing scientific names of the ebony family would have caused too much confusion. The family name ‘Ebenaceae’ has therefore been conserved according to the International Code of Botanical Nomenclature.

Ebonies at Dokmai Garden:

Diospyros decandra: Large, yellow and heavenly fragrant edible fruits. Leaves light green.

Diospyros digyna: Central American species with large edible fruits with a black interior.

Diospyros ehretioides: Egg-shaped and glabrous leaves, used for making mai dat.

Diospyros malabarica: Black smooth bark and long glabrous leaves.

Diospyros mollis: Small leaves, hardest wood in the world?

Diospyros montana: Leaves with a heart-shaped base.

Text & Photo: Eric Danell