Leaves opposite, alternate or irregularly arranged, sometimes with 3 or more prominent longitudinal veins; petiolate or sessile.
Inflorescences terminal or axillary, spike- or head-like, the terminal bud usually growing on, occasionally aborting. Flowers 5-merous, white, yellowish, pink, red or mauve. Sepals small, triangular to semicircular. Petals free. Stamens numerous, fused into bundles opposite the petals; anthers dorsifixed, versatile. Ovary half-inferior, 3-locular, with several to many erect ovules in each loculus; style filiform, stigma simple or capitate.
Fruit a loculicidal capsule, only rarely exserted from the fruiting hypanthium; seeds linear.
| | Key to the species | |
| 1 | Leaves usually less than 4 mm long, sessile, appressed | Melaleuca irbyana |
| Leaves mostly more than 5 mm long, petiolate or sessile | 2 |
| 2 | Leaves opposite or more or less opposite | 3 |
| Leaves scattered, alternate or irregularly arranged (including irregularly whorled)
Back to 1 | 11 |
| 3 | Flowers red; staminal bundles more than 20 mm long | Melaleuca hypericifolia |
| Flowers mauve, pink, white or yellowish; staminal bundles less than 20 mm long
Back to 2 | 4 |
| 4 | Inflorescences lateral from older stems | 5 |
| Inflorescences terminal, subterminal or in the upper axils
Back to 3 | 6 |
| 5 | Flowers white (sometimes tinged with pink), in few-flowered clusters | Melaleuca acuminata |
| Flowers pink to deep mauve, in short spikes
Back to 4 | Melaleuca thymifolia |
| 6 | Stamens with claw usually less than 3 mm long, each bundle consisting of up to 20 stamens | 7 |
| Stamens with claw usually more than 4 mm long, each bundle with more than 30 stamens
Back to 4 | 10 |
| 7 | Leaves with 5–7 longitudinal veins, ovate to broad-ovate | Melaleuca squarrosa |
| Leaves with 3 longitudinal veins, sometimes obscurely so, linear to broad-ovate
Back to 6 | 8 |
| 8 | Leaves channelled on upper surface, convex on each side of the midvein | Melaleuca biconvexa |
| Leaves not channelled, upper surface flat or concave
Back to 7 | 9 |
| 9 | Leaves ovate, at least 2 mm wide; inflorescences a few-flowered spikes or heads, less than 1 cm long | Melaleuca tortifolia |
| Leaves linear to narrow-ovate, less than 2 mm wide; inflorescences many-flowered spikes, more than 2 cm long
Back to 8 | Melaleuca densispicata |
| 10 | Staminal claws 8–15 mm long; fruit with included valves | Melaleuca linariifolia |
| Staminal claws 4–8 mm long; fruit usually with exserted valves
Back to 6 | Melaleuca trichostachya |
| 11 | Fruit in globose or ellipsoidal clusters; flowers in globose heads or short spikes | 12 |
| Fruit scattered or in cylindrical groups; flowers in spikes or terminal clusters
Back to 2 | 15 |
| 12 | Leaves and calyx lobes pubescent | Melaleuca glomerata |
| Leaves and calyx lobes glabrous or glabrescent
Back to 11 | 13 |
| 13 | Leaves with apex curved or hooked, leaves terete | 14 |
| Leaves with apex straight, leaves mostly flat
Back to 12 | Melaleuca nodosa |
| 14 | Fruit cluster tightly packed | Melaleuca uncinata |
| Fruit cluster loosely packed (‘peg-like’)
Back to 13 | Melaleuca interioris |
| 15 | Leaves flat, more than 3 cm long, petiolate, usually with 5 prominent longitudinal veins | Melaleuca quinquenervia |
| Leaves not as above
Back to 11 | 16 |
| 16 | Leaves sessile, acute to acuminate, with more than 4 longitudinal veins (sometimes obscure) | 17 |
| Leaves at least shortly petiolate, usually 1-veined (except Melaleuca squamea)
Back to 15 | 18 |
| 17 | Leaves narrow-ovate to ovate, 1–3 mm wide, with 5–11 longitudinal veins; bark hard | Melaleuca bracteata |
| Leaves ovate to broad-ovate, 2–6 mm wide, with more than 11 longitudinal veins; bark papery
Back to 16 | Melaleuca styphelioides |
| 18 | Leaves more than 3 mm wide | 19 |
| Leaves less than 3 mm wide
Back to 16 | 21 |
| 19 | Hypanthia and rachis of inflorescences more or less glabrous | Melaleuca groveana |
| Hypanthia and rachis of inflorescences markedly hairy
Back to 18 | 20 |
| 20 | Fruit 5–7 mm diam | Melaleuca deanei |
| Fruit 3–5 mm diam
Back to 19 | Melaleuca sieberi |
| 21 | Leaves terete, c. 0.5 mm diam.; flowers pink | Melaleuca diosmatifolia |
| Leaves flat or lower surface concave, c. 1–2 mm wide; flowers white to pink or purple
Back to 18 | 22 |
| 22 | Staminal claw more than 5 mm long | 23 |
| Staminal claw up to 4 mm long
Back to 21 | 24 |
| 23 | Inflorescences terminal or axillary, borne at the ends of branchlets; bark papery | Melaleuca alternifolia |
| Inflorescences axillary, borne low on the branchlets; bark corky or hard
Back to 22 | Melaleuca armillaris |
| 24 | Young branchlets and inflorescence axes villous | 25 |
| Young branchlets and inflorescence axes pubescent or tomentose
Back to 22 | 26 |
| 25 | Leaves with 3–5 longitudinal veins; flowers purple to pink | Melaleuca squamea |
| Leaves with only 1 vein; flowers white or pale yellow
Back to 24 | Melaleuca capitata |
| 26 | Bark papery, fibrous-papery or flaky | 27 |
| Bark hard, rough or corky
Back to 24 | 30 |
| 27 | Leaves linear; staminal claw to 2 mm long | 28 |
| Leaves narrow-elliptic; staminal claw 2–3.5 mm long
Back to 26 | 29 |
| 28 | Leaves 7–15 mm long; fruit 2.5–4 mm long | Melaleuca ericifolia |
| Leaves 4–9 mm long; fruit 4–5 mm long (Lord Howe Island)
Back to 27 | Melaleuca howeana |
| 29 | Leaves with at least 1 conspicuous vein; stamens 20–40 per bundle; sepals not persistent in fruit | Melaleuca decora |
| Leaves with 1 obscure vein; stamens 11–25 per bundle; sepals more or less persistent in fruit
Back to 27 | Melaleuca sieberi |
| 30 | Leaves linear; stamens 4–7 per bundle; fruit 2–4 mm diam. ; leaves with raised oil glands | Melaleuca parvistaminea |
| Leaves linear to narrow-elliptic; stamens 8–14 per bundle; fruit 4–5 mm diam.; leaves with small oil glands
Back to 26 | Melaleuca lanceolata |
