Leaves mostly alternate, margins recurved, revolute or flat; mostly shortly petiolate; stipules absent.
Flowers axillary, usually solitary, pedunculate or almost sessile, with 2–10 basal bracts, calyx-like, persistent or shed early. Perianth usually of 4 or 5 petaloid segments, imbricate. Male flowers with numerous stamens, filaments fused to form a column. Female perianth segments usually smaller and narrower than the male segments, sometimes enlarged around the fruit; ovary 3-locular, 1 ovule in each loculus; styles mostly 3, branched.
| | Key to the species | |
| 1 | Leaves 1–4 mm wide, margins recurved to revolute | 2 |
| Leaves mostly more than 4 mm wide, margins recurved or flat | 13 |
| 2 | Stellate hairs present, particularly on young growth and lower surface of leaves | 3 |
| Entire plant glabrous or nearly so
Back to 1 | 12 |
| 3 | Ovary sparsely hairy to glabrous; capsule glabrous | 4 |
| Ovary densely hairy; capsule hairy, sometimes more or less glabrous with age
Back to 2 | 6 |
| 4 | Leaves linear, margins revolute to midrib | 5 |
| Leaves linear-lanceolate, margins recurved, but not to the midrib. Narrow-leaved form
Back to 3 | Bertya pomaderroides |
| 5 | Fruiting perianth not enlarged; calyx more or less equal to half the length of the capsule | Bertya linearifolia |
| Fruiting perianth enlarged, enclosing the capsule
Back to 4 | Bertya gummifera |
| 6 | Leaves strongly revolute, 0.5–2 mm wide; midrib more or less concealed on lower surface | 7 |
| Leaves recurved to revolute, mostly 2–4 mm wide; midrib clearly visible on lower surface
Back to 3 | 8 |
| 7 | Flowers small, female perianth 3–4 mm long; leaves 0.5–1.5 mm wide, lower surface whitish tomentose | Bertya rosmarinifolia |
| Flowers larger, female perianth 4–6 mm long; leaves mostly 2 mm wide, lower surface mostly yellow-brown to greyish tomentose
Back to 6 | Bertya tasmanica |
| 8 | Lower surface of leaves with a dense tomentum of fine short, or stellate hairs; female perianth segments mostly glabrous adaxially | 9 |
| Lower surface of leaves with a medium covering of larger hairs (individual hairs easily seen); female perianth segments tomentose
Back to 6 | Bertya mollissima |
| 9 | Leaves linear to oblong or narrow-obovate, usually less than 30 mm long; flowers on peduncles | 10 |
| Leaves linear to oblanceolate or narrow-elliptic, 10–60 mm long; flowers more or less sessile
Back to 8 | 11 |
| 10 | Plant viscid, with marginal glands at the base of, and either side of the midrib | Bertya oblonga |
| Plant not viscid, glands absent
Back to 9 | Bertya riparia |
| 11 | Leaves 10–60 mm long, margins recurved to revolute; female perianth segments much enlarged under fruit, not distinctly fused below the middle | Bertya oleifolia |
| Leaves 10–35 mm long, margins recurved; female perianth segments not enlarged under fruit, distinctly fused below the middle
Back to 9 | Bertya ingramii |
| 12 | Fruiting perianth much enlarged, enclosing the capsule; leaves c. 2 mm wide, 10–30 mm long; flowers almost sessile | Bertya glandulosa |
| Fruiting perianth not enlarged; leaves c. 1 mm wide, 10–20 mm long; flowers on peduncles 1–2 mm long
Back to 2 | Bertya cunninghamii |
| 13 | Capsule glabrous or with scattered stellate hairs at first and then becoming glabrous; leaves flat or margins slightly recurved | 14 |
| Capsule with persistent hairs; margins of leaves recurved to revolute
Back to 1 | 17 |
| 14 | Flowers on stout peduncles 3–5 mm long; leaves mostly 4–8 mm wide | Bertya findlayi |
| Flowers on slender peduncles or sessile; leaves mostly 4–25 mm wide
Back to 13 | 15 |
| 15 | Flowers on slender peduncles 5–25 mm long; leaves mostly 4–15 mm long | 16 |
| Flowers sessile; leaves mostly 4–25 mm long
Back to 14 | Bertya opponens |
| 16 | Leaves 10–50 mm long, 5–15 mm wide, margins flat, finely sinuate; entire plant covered with persistent loose tomentum of rusty-stellate, mostly stalked hairs; ovary densely tomentose | Bertya brownii |
| Leaves mostly 10–30 mm long, 3–12 mm wide, margins flat or slightly recurved; plants with a covering of denser, whitish to rusty, more or less sessile, stellate hairs, often becoming glabrous; ovary glabrous
Back to 15 | Bertya pomaderroides |
| 17 | Leaves mostly opposite; ovary and capsule densely villous; bracts 4, rarely 6, perianth segments mostly 4 | Bertya opponens |
| Leaves alternate; ovary and capsule with medium-dense covering of shorter hairs; bracts 5–8, perianth segments 5
Back to 13 | 18 |
| 18 | Fruiting perianth much enlarged, c. 8 mm long, at least as long as capsule; leaves oblong to oblanceolate or narrow-elliptic, 10–60 mm long, 3–7 mm wide; perianth mostly glabrous, resinous | Bertya oleifolia |
| Fruiting perianth not enlarged, 2–3 mm long, shorter than capsule; leaves oblong, 5–20 mm long, 2–5 mm wide; perianth usually hairy
Back to 17 | Bertya mollissima |
