Leaves alternate or opposite, often scale-like, or simple or 1-foliolate; ± shortly petiolate; stipules usually small.
Flowers axillary, solitary or a few together; each flower subtended by a series of bracts and a pair of bracteoles, usually on the pedicel. Calyx 5-toothed, upper 2 teeth usually broader and united higher than lower 3. Petals clawed, mostly orange to yellow, often with some dark red to purplish brown markings; standard ± circular or reniform, about twice as long as calyx; wings narrow; keel broader than wings and shorter or longer than standard. Stamens monodelphous, sheath split on upper side; anthers uniform, dorsifixed, versatile. Ovary stipitate or ± sessile; 1- to many-ovuled.
| | Key to the species | |
| 1 | Plants leafless (scale leaves or leaves sometimes present on juvenile growth); branches flat and distinctly winged (i.e. cladodes), | 2 |
| Leaves present; branches terete or sometimes flat but never broadly winged. | 6 |
| 2 | Flowers red, >15 mm long; keel longer than standard; ovules c. 20; inland species, west from Nyngan district. | Bossiaea walkeri |
| Flowers mostly yellow or orange, often with reddish markings, <15 mm long; keel usually shorter than standard; ovules 4–10; species of the coast and ranges.
Back to 1 | 3 |
| 3 | Cladodes 2–4 mm wide; pods usually 1–2 cm long; seeds 2–4. | Bossiaea riparia |
| Cladodes usually 4–15 mm wide; pods 2.5–5 cm long; seeds usually 6–10.
Back to 2 | 4 |
| 4 | Bracteoles caducous; erect shrub to 2.5 m high. | Bossiaea bracteosa |
| Bracteoles persistent; erect or decumbent shrubs 1–1.5 m high.
Back to 3 | 5 |
| 5 | Flowers mostly 6–10 mm long; bracteoles inserted at or below middle of pedicel, tips not reaching to receptacle; ultimate branches of cladodes mostly 2–4 mm wide. | Bossiaea ensata |
| Flowers mostly 10–14 mm long; bracteoles inserted at or above middle of pedicel, tips reaching to receptacle; ultimate branches of cladodes mostly 4–6 mm wide.
Back to 4 | Bossiaea scolopendria |
| 6 | Leaves opposite or if alternate then triangular with long fine points; ovary stipitate. | 7 |
| Leaves alternate (but not triangular with long, fine points); ovary sessile or stipitate.
Back to 1 | 9 |
| 7 | Leaves with lamina ± circular; stems glabrous, often reddish or yellowish. | Bossiaea lenticularis |
| Leaves with lamina not circular; stems pubescent with appressed or spreading hairs, usually green to brown.
Back to 6 | 8 |
| 8 | Young stems ± flat, hoary or sparsely pubescent with short, appressed hairs; leaves narrow-elliptic to narrow-ovate, upper surface smooth; flowers on pedicles ≤5 mm long. | Bossiaea kiamensis |
| Young stems terete, usually with a ± dense pubescence of longer, spreading hairs; leaves triangular to ovate or lanceolate, upper surface ± scabrid; flowers on pedicels 5–20 mm long.
Back to 7 | Bossiaea cinerea |
| 9 | Stipules conspicuous, 5–10 mm long; leaves usually 10–20 mm long, apex ± pungent-pointed with a recurved apex. | Bossiaea stephensonii |
| Stipules small and mostly inconspicuous, 1–3 mm long; leaves 2–35 mm long, not pungent-pointed.
Back to 6 | 10 |
| 10 | Branches spinescent. | Bossiaea obcordata |
| Branches not spinescent.
Back to 9 | 11 |
| 11 | Keel much longer than standard, c. 20 mm long; leaves 10–35 mm long; pods 3–5 cm long; seeds mostly 5–8; erect shrub with terete branches; confined to far north coast near the Qld border (NC). | Bossiaea rupicola |
| Keel ± equal with standard, ≤10 mm long; leaves mostly <10 mm long or if longer than either plants prostrate or branchlets of young growth flattened; widespread, not confined to the far north coast.
Back to 10 | 12 |
| 12 | Ovary and pods pubescent; stems pubescent. | 13 |
| Ovary glabrous or some hairs present on apex and margins; mature pods glabrous or margins ciliate; stems ± glabrous, glabrescent or pubescent.
Back to 11 | 14 |
| 13 | Most leaves about as long as broad, 1–3.5 mm long and 1–3 mm wide; pods 5–10 mm long and usually with 2 or 3 seeds; south from the Orange district (CT, ST). | Bossiaea foliosa |
| Most leaves longer than broad, 5–10 mm long and 2–7 mm wide; pods 10–30 mm long and with 5–8 seeds; north from Rylstone district (NC, NT, NWS, CWS).
Back to 12 | Bossiaea scortechinii |
| 14 | Pedicels 6–20 mm long, longer than calyx. | 15 |
| Pedicels 2–5 mm long, shorter than calyx.
Back to 12 | 16 |
| 15 | Leaves with petiole 2–5 mm long, lamina 3–15 mm long; leaves ± distant; pedicels 10–20 mm long. | Bossiaea prostrata |
| Leaves with petiole c. 1 mm long, lamina 2–5 mm long, ± closely spaced; pedicels 6–10 mm long.
Back to 14 | Bossiaea buxifolia |
| 16 | At least young stems hairy, lower surface of leaves hairy; stems terete. | 17 |
| Stems ± glabrous, lower surface of leaves glabrous; young stems distinctly flattened.
Back to 14 | 18 |
| 17 | Erect shrubs 1–2 m high; ovary and pods glabrous; pods 1–1.7 mm long, usually with 1–3 seeds; near lake Burragorang and Nerriga area (CC, ST). | Bossiaea oligosperma |
| Prostrate or decumbent shrub; ovary and pods ± ciliate; pods 2–2.5 mm long, mostly with 5–8 seeds; north from Sutton Forest district (NC, CC, NT, CT).
Back to 16 | Bossiaea neoanglica |
| 18 | Leaves mostly rhombic to obovate, ± similar on the one plant, mostly 3–10 mm long; seeds usually 2–4. | Bossiaea rhombifolia |
| Leaves ovate to almost linear, of variable shape on the one plant, mostly 10–30 mm long; seeds mostly 6–8.
Back to 16 | Bossiaea heterophylla |
