Ulmaceae

This is primarily a tropical family, represented in Australia by a few native and introduced species occurring widely across tropical and central Australia north of the Tropic of Capricorn or (the introduced Ulmus), naturalised in southern Australia.

Characteristic features of the family Ulmaceae in Australia include:

• trees or large shrubs with alternate, simple, often toothed leaves, frequently 3-veined from the base
  
• flowers inconspicuous, unisexual, greenish, with 4–8 small, free perianth lobes at the base of the superior ovary (female flowers) or enclosing the stamens (male flowers); styles usually 2
  
• fruit dry and papery, winged (Ulmus) or an orange, red or black drupe

Description

Evergreen or deciduous trees or shrubs. Internal secretions not obvious. Plants glabrous, or with simple, glandular or non-glandular, unicellular or uniseriate hairs. Leaves alternate and spiral, or distichous, petiolate or subsessile. Stipules distinct and free from the petiole, or intrapetiolar, scale-like, or membranous, or green and leafy, falling off early. Lamina simple, symmetric or conspicuously asymmetric, lanceolate, ovate, elliptic, oblanceolate, obovate or oblong; base cuneate, rounded, cordate, lobed, auriculate or oblique; margins entire, dentate, serrate or rarely spinose, ±flat; venation pinnate, or parallel, with the midrib conspicuous, and the tertiary venation reticulate or not; surfaces not punctate; herbaceous. Domatia present. Male and female flowers occurring on the same plant, or with all the flowers bisexual, or with bisexual flowers and either male or female flowers occurring together. Inflorescences terminal or axillary, consisting of glomerules, racemes, panicles, cymes or solitary flowers. Bracts present or absent. Pollination by insects or wind. Flowers sessile or stalked. Perianth regular, of 1 whorl only, with 4–8, free or fused, sepaloid segments, imbricate or valvate in bud; cup-shaped or bell-shaped; herbaceous; bases without appendages. Fertile stamens 4–8, opposite to and free of or at least partly fused to the perianth, free of the ovary and style, distinct from each other, all ±equal. Staminodes present or absent. Anthers dorsifixed, not versatile, opening outwards, sideways or inwards by longitudinal slits, 2-celled. Ovary superior and sessile. Carpels 2–3, fused; ovary with 1 locule. Style terminal, branching from the base. Ovule 1, stalked; placentation apical. Fruit a dry or fleshy indehiscent nut, or a samara, or a drupe; the perianth on the maturing fruit deciduous, or dry and persistent. Disseminule macro-surface featureless or winged; micro-surface ±smooth, yellow, green, brown or black, dull. Seed 1 per fruit. Aril absent. Cotyledons 2. Embryo straight or curved.
(Note: this description has been generated from the coded data compiled for the key. Any errors in the key data will be reflected in the descriptions.)

A treatment of the family Ulmaceae has been published in:
Flora of Australia 3: 4-13.

Australian genera of Ulmaceae (as recognised for the Flora of Australia)

† = some species native, others introduced
* = all species introduced

Aphananthe
†Celtis
Trema
*Ulmus

Aphananthe philippinensis (fruits)
Photo: M.Fagg © M.Fagg 

Celtis amblyphylla (flowers)
Photo: D.Jones © D.Jones 

Celtis paniculata (flowers)
Photo: G.Sankowski © Zodiac Publications