Family Eupomatiaceae

Eupomatiaceae Endl.

Habit and leaf form. Trees and shrubs; bearing essential oils; leptocaul. Mesophytic. Leaves alternate; distichous; petiolate; non-sheathing; gland-dotted, or not gland-dotted; aromatic, or without marked odour; simple; epulvinate. Lamina entire; pinnately veined; cross-venulate. Leaves exstipulate. Lamina margins entire. Leaves without a persistent basal meristem.

Leaf anatomy. Stomata present; mainly confined to one surface (abaxial); paracytic.

Lamina weakly dorsiventral; without secretory cavities. The mesophyll with spherical etherial oil cells, or without etherial oil cells (?). Minor leaf veins without phloem transfer cells (1 genus).

Stem anatomy. Nodes penta-lacunar, or multilacunar (with five or more traces). Secondary thickening developing from a conventional cambial ring. Xylem with fibre tracheids. Vessel end-walls oblique; scalariform. Wood parenchyma apotracheal and paratracheal. Sieve-tube plastids P-type; type I (b).

Reproductive type, pollination. Plants hermaphrodite. Pollination entomophilous; via beetles.

Inflorescence, floral, fruit and seed morphology. Flowers solitary (usually), or aggregated in ‘inflorescences’ (sometimes 2–3 together); bracteate. Bracts calyptrate (each flower covered initially by one calyptrate bract, which falls entire). Flowers medium-sized; calyptrate; acyclic. The androecium acyclic and the gynoecium acyclic.

Perianth absent.

Androecium 25–100 (i.e. ‘many’). Androecial members maturing centripetally; free of one another; spiralled. Androecium including staminodes. Staminodes 15–50 (‘many’); internal to the fertile stamens (the inner members being sterile); petaloid. Stamens about 5–15 (‘the few outer members’); laminar to petaloid (the outer, fertile members narrow). Anthers basifixed, or adnate; non-versatile; dehiscing by longitudinal valves; extrorse (the thecae abaxial); appendaged (with a prolonged connective). Microsporogenesis simultaneous. The initial microspore tetrads tetrahedral, or isobilateral, or decussate, or linear (occasionally). Pollen grains aperturate; 2 aperturate, or 3 aperturate; sulculate, or zoniaperturate.

Gynoecium 13–68 carpelled; apocarpous; eu-apocarpous to semicarpous (carpels spiralled); partly inferior (sunken in the top-shaped receptacle). Carpel incompletely closed; 2–11 ovuled. Placentation marginal (ventral). Ovules non-arillate; anatropous; bitegmic.

Fruit fleshy; an aggregate. The fruiting carpels coalescing into a secondary syncarp (and sunken). The fruiting carpel indehiscent. Fruit enclosed in the fleshy receptacle. Seeds endospermic. Endosperm ruminate; oily. Embryo well differentiated (very small).

Seedling. Germination phanerocotylar.

Physiology, biochemistry. Not cyanogenic. Alkaloids absent (2 species). Iridoids not detected. Proanthocyanidins present; cyanidin. Flavonols absent. Ellagic acid absent.

Geography, cytology. Temperate to tropical. New Guinea and coastal Eastern Australia. 2n = 20.

Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Magnoliiflorae; Annonales. Cronquist’s Subclass Magnoliidae; Magnoliales. APG 3 core angiosperms; Superorder Magnolianae; Order Magnoliales.

Species 2. Genera 1; only genus, Eupomatia.