Ebenaceae

Growth Form and Habit

Plants are typically trees or shrubs, ranging from small shrubs to large trees. They are often evergreen but can be deciduous in temperate or seasonally dry areas. Many species, especially in Diospyros, develop very hard, dense, dark (often black) heartwood known as ebony.

Leaves

Leaves are usually arranged alternately (spirally, sometimes appearing 2-ranked), rarely opposite or whorled. They are simple with typically entire margins, and often have a leathery (coriaceous) texture. Leaves lack stipules. Small black dots (glandular structures) may be visible on the leaf undersurface in some species.

Inflorescence

Flowers are borne in small, axillary cymes or fascicles (clusters), or are sometimes solitary, especially female flowers.

Flowers

Flowers are usually unisexual (plants typically dioecious, less commonly monoecious or polygamous), sometimes bisexual (Lissocarpa). They are radially symmetrical (actinomorphic) and typically (3-)4-5(-7)-merous. Flowers are often relatively small and inconspicuous, usually whitish, cream, yellowish, or pinkish.

• Calyx: Consists of (3-)4-5(-7) sepals, which are fused at the base into a calyx tube. The calyx is notably persistent and often enlarges considerably after flowering, becoming leathery or woody and forming a cup or saucer structure at the base of the fruit.
• Corolla: Consists of (3-)4-5(-7) petals that are fused (sympetalous) for at least part of their length, typically forming an urn-shaped (urceolate), bell-shaped (campanulate), or tubular corolla with spreading lobes. The corolla usually falls off after flowering (deciduous).
• Androecium (Male or Bisexual Flowers): Stamens usually number (1-)2-4 times the number of corolla lobes (e.g., 8-20 stamens for a 4- or 5-lobed corolla), often arranged in 1-4 whorls. Filaments are typically short and attached to the base of the corolla tube (epipetalous) or the receptacle. Filaments can be free or fused in pairs or bundles. Anthers open by longitudinal slits. Male flowers usually contain a rudimentary, non-functional pistil (pistillode).
• Gynoecium (Female or Bisexual Flowers): Features a superior ovary composed of 2-8 (up to 16) fused carpels, forming an equal number of locules (chambers), or sometimes twice as many locules due to the formation of false septa. Styles are usually 2-8, free or fused only at the base, often forked (bifid). Each locule (or half-locule) typically contains 1 (sometimes 2) pendulous ovules attached near the apex (apical-axile placentation). Female flowers often possess sterile stamens (staminodes).

Fruits and Seeds

The fruit is a fleshy or sometimes leathery berry, often globose or ovoid. It typically contains 1 to several (up to 16) large seeds. A highly characteristic feature is that the berry is almost always subtended or partially enclosed by the persistent and enlarged calyx. Seeds are large with abundant, very hard endosperm (which can be smooth or ruminate - mottled/furrowed).

Chemical Characteristics

Plants often contain tannins (contributing to astringency of unripe fruit) and characteristic naphthoquinones (like diospyrin), which contribute to the dark color of the heartwood and bark. Triterpenoids are also common.