Description: Trees or shrubs, usually glabrous.
Leaves opposite, venation usually distinct, petiolate.
Inflorescences usually panicles, terminal or axillary, occasionally ramiflorous or cauliflorous. Flowers 4- or rarely 5-merous. Calyx lobes usually small, persistent in fruit. Petals free or occasionally forming calyptra. Stamens numerous; anthers dorsifixed, versatile, lobes parallel. Ovary ± inferior, 2- or rarely 3-locular; ovules several on an axile placenta; style about as long as or slightly exceeding the stamens, stigma small.
Fruit succulent, flesh firm or spongy, usually crowned by the persistent calyx lobes; seed usually solitary, rarely 2 or more; testa soft, leathery or papery; cotyledons thick, free from each other.
Distribution and occurrence: World: >500 spp., trop. & subtrop. Afr., Asia, Pac. Aust.: 52 spp. (47 spp. endemic), Qld, N.S.W., N.T., W.A.
Many species are cultivated as ornamental trees; the flowers with their mass of coloured stamens, often brightly coloured fruit and reddish new growth add to their appeal. The dried flower buds of S. aromaticum (L.) Merr. & Perry ar the commercial cloves used in flavouring.
Taxa not yet included in identification key
Syzygium fullagarii
| | Key to the species | |
| 1 | Leafy twigs 4-angled to shortly 4-winged, wings joining above each node to produce a small pocket | Syzygium australe |
| Leafy twigs terete to 4-angled, pockets never forming above the node | 2 |
| 2 | Leaves with intramarginal vein poorly developed, main lateral veins irregularly looping well inside the margins | Syzygium hodgkinsoniae |
| Leaves with intramarginal veins close to the margins, usually well developed
Back to 1 | 3 |
| 3 | Petals cohering and shed as a calyptra | 4 |
| Petals free and spreading
Back to 2 | 5 |
| 4 | Inflorescences terminal and axillary; fruit purplish blue | Syzygium francisii |
| Inflorescences produced on the older stems below the leaves; fruit white
Back to 3 | Syzygium moorei |
| 5 | Fruit pink to red | 6 |
| Fruit bluish to purple or magenta
Back to 3 | 7 |
| 6 | Hypanthium short, 3–6 mm long; fruit 9–12 mm long, 7–11 mm diam.; leaves 2.5–7 cm long, 1–3 cm wide | Syzygium luehmannii |
| Hypanthium 6–14 mm long; fruit 13–20 mm long, 11–18 mm diam.; leaves 4–12 cm long, 2–5.5 cm wide
Back to 5 | Syzygium corynanthum |
| 7 | Oil glands in leaves very numerous, rather large and readily visible to the naked eye | Syzygium oleosum |
| Oil glands small and scattered, or obscure, not readily visible with the naked eye
Back to 5 | 8 |
| 8 | Seeds containing 2 or more embryos of various sizes; fruit more or less ovoid to globose | Syzygium paniculatum |
| Seeds containing only one embryo; fruit depressed-globose
Back to 7 | Syzygium crebrinerve |
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