| Key to the genera | |
1 | Fruit succulent. | 2 |
| Fruit dry. | 18 |
2 | Inflorescences usually terminal and many-flowered; seed relatively large, usually solitary. | 3 |
| Inflorescences axillary, 1 or few-flowered; seed usually small, mostly >1 per fruit, or sometimes only 1. Back to 1 | 5 |
3 | Seeds with a papery testa and separate, green cotyledons. | Syzygium |
| Seeds with no obvious testa, cotyledons fused with a conspicuous dark inclusion spreading through the centre. Back to 2 | 4 |
4 | Fruit apex topped by the persistent, cylindrical, unexpanded free portion of the hypanthium; intercotyledonary inclusion spreading from the base of the fruit. | Waterhousea |
| Fruit apex topped by the circular remnant of the hypanthium rim; intercotyledonary inclusion spreading from the summit of the fruit. Back to 3 | Acmena |
5 | Leaves usually <10 mm wide; flowers solitary in leaf axils; plants of sclerophyll forest, rainforest, heath and scrubland. | 6 |
| Most leaves >10 mm wide; flowers either solitary, clustered or in axillary raceme-like or panicle-like inflorescences; plants of rainforests, sometimes on their margins or in sclerophyll forest. Back to 2 | 7 |
6 | Mature fruit white to greyish or bluish green, often with darker spots; spreading or bushy shrubs to 2 m high; coastal districts and adjacent ranges north from the Sydney district. | Austromyrtus |
| Mature fruit green turning red or black; shrubs or small trees to 12 m high; rare, only on the McPherson and Nightcap Ranges. Back to 5 | Uromyrtus |
7 | Mature fruit yellow, orange or red. | 8 |
| Mature fruit purple or black. Back to 5 | 13 |
8 | Fruit vertically ribbed, bright red. | Eugenia |
| Fruit not vertically ribbed, usually yellow to orange, sometimes red. Back to 7 | 9 |
9 | Sepals and petals mostly 4. | 10 |
| Sepals and petals mostly 5, or occasionally some 4. Back to 8 | 11 |
10 | Leaves 3-veined from base; fruit red turning blackish when mature. | Rhodamnia |
| Leaves not 3-veined from base; fruit yellow to orange. Back to 9 | Gossia |
11 | Mature fruit >2 cm diam.; sepals cohering in the bud, splitting longitudinally at flowering. | Psidium |
| Mature fruit <2 cm diam.; sepals free in the bud. Back to 9 | 12 |
12 | Leaves 1–3 cm wide; ovary 3-locular; mature fruit 5–7 mm diam., topped by erect persistent sepals; petals 4–6 mm long. | Archirhodomyrtus |
| Leaves 2.5–6.5 cm wide; ovary 4-locular , becoming multi-locular by development of false septa; mature fruit 10–15 mm diam. with persistent sepals reflexed; petals 7–10 mm long. Back to 11 | Rhodomyrtus |
13 | Sepals and petals 4. | 14 |
| Sepals and petals 5. Back to 7 | 15 |
14 | Leaves 3-veined from base. | Rhodamnia |
| Leaves not 3-veined from base. Back to 13 | Lenwebbia |
15 | Fruit vertically lobed; ovary 4- or 5-locular. | Decaspermum |
| Fruit not vertically lobed; ovary 2- or 3-locular. Back to 13 | 16 |
16 | Petals 2–5 mm long; testa hard and bony. | 17 |
| Petals 5–7 mm long; testa membranous to papery. Back to 15 | Pilidiostigma |
17 | Anthers with a conspicuous apical appendage; flowers and fruit usually solitary, pendent. | Uromyrtus |
| Anthers topped only by a small apical gland; flowers and fruit occasionally solitary, but usually >1, not pendent. Back to 16 | Gossia |
18 | Flower buds covered with a calyptra formed from the fused perianth segments. | 19 |
| Flower buds not covered with a calyptra. Back to 1 | 20 |
19 | Inflorescences compound, terminal or axillary and anthers versatile and opening by parallel slits and disc steeply depressed in fruit. | Corymbia |
| Inflorescences, anthers and fruit not a combination of the above characters. Back to 18 | Eucalyptus |
20 | Stamens grouped (usually distinctly fused) into 5 bundles opposite the petals | 21 |
| Stamens not in 5 bundles, usually free but occasionally fused into a short tube at the base. Back to 18 | 24 |
21 | Fruit included in the hypanthium or barely exserted; seeds linear. | 22 |
| Fruit exserted from the hypanthium; seeds flat, winged. Back to 20 | Tristaniopsis |
22 | Flowers sessile, aggregated into head- or spike-like conflorescences. | Melaleuca |
| Flowers pedicellate, inflorescences cymose. Back to 21 | 23 |
23 | Leaves opposite and decussate; oil ducts absent from the petioles. | Tristania |
| Leaves alternate along branchlets but clustered in false whorls at the end of the branchlets; oil ducts, containing milky oil, present in the petioles. Back to 22 | Lophostemon |
24 | Leaves opposite. | 25 |
| Leaves alternate. Back to 20 | 41 |
25 | Most leaves >5 mm wide. | 26 |
| Most leaves <5 mm wide. Back to 24 | 29 |
26 | Fruit indehiscent; hypanthium papery to leathery | 27 |
| Fruit a loculicidal capsule; hypanthium woody Back to 25 | 28 |
27 | Leaves with a strong aniseed smell when crushed, margins undulating. | Anetholea |
| Leaves not strongly smelling of when crushed, margins ± flat. Back to 26 | Backhousia |
28 | Flowers sessile, 7 per inflorescence; capsules fused in a woody syncarp. | Syncarpia |
| Flowers pedicellate, numerous; capsules usually ribbed. Back to 26 | Angophora |
29 | Ovary and fruit 2- or 3-locular. | 30 |
| Ovary and fruit 1-locular. Back to 25 | 38 |
30 | Stamens exceeding the petals. | Kunzea |
| Stamens shorter than the petals. Back to 29 | 31 |
31 | Ovary and fruit 2-locular. | Baeckea |
| Ovary and fruit 3-locular. Back to 30 | 32 |
32 | Anthers adnate to filament, dehiscing by pores or short parallel slits. | 33 |
| Anthers versatile, dehiscing by long parallel slits. Back to 31 | 35 |
33 | Inflorescence usually of solitary flowers; bracteoles 2; peduncles generally shorter than pedicels | 34 |
| Inflorescence usually of (2–)3 or more flowers; bracteoles 4–many, clustered at the apex of the peduncle; peduncles generally longer than pedicels Back to 32 | Sannantha |
34 | Sepals ‘compound’, the dorsal lobe often acute; summit of fruit slightly exserted from the fruiting hypanthium; leaves acute to obtuse | Kardomia |
| Sepals simple, obtuse; summit of fruit at or within the rim of the fruiting hypanthium; leaves with a small, recurved mucro Back to 33 | Harmogia |
35 | Ovules and seeds D-shaped, angular. | Baeckea |
| Ovules and seeds ± reniform, not angular. Back to 32 | 36 |
36 | Some stamens opposite centre of petals | 44 |
| No stamens opposite centre of petals. Back to 35 | 37 |
37 | Stamens 5–8; ovules 2 per loculus. | Ochrosperma |
| Stamens 14–18; ovules 8–13 per loculus. Back to 36 | Triplarina |
38 | Stamens 10, twice as many petals, alternating with 10 staminodes; style long-exserted. | 39 |
| Stamens 5–12, up to twice as many as petals, staminodes lacking; style included or very shortly exserted. Back to 29 | 40 |
39 | Sepals terminating in one or more slender processes. | Homoranthus |
| Sepals lacking slender processes, entire or shortly ciliate. Back to 38 | Darwinia |
40 | Stamens <10, usually opposite the sepals; anther connective gland prominent, clavate or ± urceolate. | Thryptomene |
| Stamens 10 or 12 or if 5 then opposite the petals; anther connective gland small, subglobose. Back to 38 | Micromyrtus |
41 | Ovary 1-locular; sepals persistent, membranous, terminating in a long, slender awn. | Calytrix |
| Ovary >1-locular; sepals persistent or not persistent, never ending in an awn. Back to 24 | 42 |
42 | Stamens considerably longer than the petals. | 45 |
| Stamens shorter, or scarcely longer, than the petals. Back to 41 | 43 |
43 | Fruit woody, woody-valved and usually persistent; seeds ± linear, longitudinally striate | Leptospermum |
| Fruit either not woody or if ± woody then the valves not woody; seeds ovoid-cuneiform, the surface reticulate Back to 42 | 44 |
44 | Flowers on the flowering shoot >2; pedicels <2mm long; fruit always 3-locular | Aggreflorum |
| Flowers on the flowering shoot usually 1, pedicels >2 mm long; fruit 3- or variably 3–5(-7)-locular Back to 43 | Gaudium |
45 | Sepals not persistent, flowers aggregated into spike-like conflorescences. | Callistemon |
| Sepals persistent, flowers in heads or solitary in the leaf axils. Back to 42 | Kunzea |
46 | Shrubs; pedicels shorter than, or as long as, the leaves; bracteoles not persistent. | Rinzia |
| Prostrate plants; pedicels longer than the leaves; bracteoles persistent. Back to | Euryomyrtus |