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 | 9 |
| 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 persistent; erect or decumbent shrubs 1–1.5 m high | 5 |
| Bracteoles caducous; erect shrub to 2.5 m high
Back to 3 | 6 |
| 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 | Upper 2 calyx lobes c. quadrangular contrasting strongly with the triangular lower lobes; pedicels exceeding floral bracts at flowering by 1–2 mm | Bossiaea fragrans |
| Calyx lobes all triangular; pedicels not or hardly exceeding the floral bracts at flowering
Back to 4 | 7 |
| 7 | Scales mostly 3–5 mm long | Bossiaea bracteosa |
| Scales mostly <2 mm long
Back to 6 | 8 |
| 8 | Cladodes dark green in fresh material; reproductive branches of cladodes usually <4 mm wide; calyx lobes <1.5 mm long | Bossiaea bombayensis |
| Cladodes grey green in fresh material; reproductive branches of cladodes usually >4 mm wide; calyx lobes ≥1.5 mm long
Back to 7 | Bossiaea grayi |
| 9 | Leaves all regularly opposite, with nodes well-spaced | 10 |
| Leaves all regularly alternate or arranged irregularly (somtimes ± opposite)
Back to 1 | 14 |
| 10 | Pods not thickly and narrowly margined or keeled above, with flattish valves; upper calyx teeth not greatly enlarged | 11 |
| Pods with a thin conspicuous wing above, valves rolling back; leaves opposite; upper calyx teeth greatly enlarged, >6 times as long as lower teeth (Platylobium)
Back to 9 | 12 |
| 11 | Leaflets with l:w ratio ≥2 | Bossiaea kiamensis |
| Leaflets with l:w ratio 0.8–1.2
Back to 10 | Bossiaea lenticularis |
| 12 | Leaves with rounded bases, never cordate | Platylobium parviflorum |
| Majority or all leaves with cordate bases
Back to 10 | 13 |
| 13 | Calyx 8–12 mm long; bracteoles 3–4 mm long; inflorescence scales hairy all over | Platylobium formosum |
| Calyx 5–8 mm long; bracteoles 4–10 mm long; inflorescence scales with glabrous body and hairy margins
Back to 12 | Platylobium montanum |
| 14 | Standard petal to c. 8 mm long, all yellow; upper calyx-lobes <1 mm wide; pods <10 mm long, hairy all over; ovaries and pods with hairs commonly pale yellow or coppery (mostly tablelands to alps) | 15 |
| Standard petal >8 mm long and/or with red markings, or if ever not with either feature then upper calyx-lobes >1 mm wide; pods >10 mm long, hairy all over or more often with valve faces glabrous; ovaries and pods with hairs white
Back to 9 | 17 |
| 15 | Leaflet halves flat or only slightly convex, margins not revolute, upper surface without tubercles or on margins only; lower surface close-appressed to sericeous | Bossiaea sericea |
| Leaflet halves markedly convex, margins commonly partly revolute, upper surface with scattered minute tubercles all over; lower surface never covered by closely appressed hairs
Back to 14 | 16 |
| 16 | Stipules >1.5 mm long; leaves transversely oblong-elliptic; bracteoles >2 mm long, extending well onto the calyx | Bossiaea distichoclada |
| Stipules <1.5 mm long; leaves broad-ovate; bracteoles ≤1 mm long, not exceeding receptacle
Back to 15 | Bossiaea foliosa |
| 17 | Apex of leaflets narrowly acute with a robust, sometimes pungent apiculum; bracteoles to c. 1 mm long, not or hardly longer than broad, inserted more than halfway along pedicel | 18 |
| Apex of leaflets not entirely as above or if ever nearly so then branchlets compressed; bracteoles mostly >1 mm long, longer than broad, inserted variously
Back to 14 | 19 |
| 18 | Leaflets with l:w ratio mostly >3; stipules opposite each other; wings purplish-brown; pedicels usually hairy | Bossiaea cinerea |
| Leaflets with l:w ratio mostly <3; stipules closely attached (commonly forming a deflexed V); wings yellow with reddish streaks at base; pedicels usually glabrous
Back to 17 | Bossiaea cordifolia |
| 19 | At least some branchlets spinescent or subspinescent (tapering to a blunt point) | Bossiaea obcordata |
| Branchlets not spinescent or tapering
Back to 17 | 20 |
| 20 | Lower calyx-lobes at least as long as the calyx-tube AND the upper lobes; calyx hairy | 21 |
| Lower calyx-lobes shorter than calyx-tube and/or shorter than the upper lobes; calyx glabrous or hairy
Back to 19 | 25 |
| 21 | Ovaries and pods with hairs restricted to sutures (rarely with hairs all over in B. prostrata); leaflet margin nearly flat; standard extensively marked red abaxially; stipules usually brown | 22 |
| Ovaries and pods with hairs all over; leaflet margin recurved to revolute; standard yellow or flushed pink abaxially; stipules mostly green
Back to 20 | 23 |
| 22 | Petioles ≤1 mm long; bracteoles usually persistent, mostly inserted in middle third of pedicel; back of standard ± solidly red | Bossiaea nummularia |
| Longest petioles >1 mm long; bracteoles usually falling, inserted in proximal third of pedicel; back of standard with long pale streaks through red markings
Back to 21 | Bossiaea prostrata |
| 23 | Leaflets predominantly obovate; pedicels mostly <5 mm long | Bossiaea obovata |
| Leaflets predominantly narrow-oblong to narrow-elliptic; pedicels mostly >5 mm long
Back to 21 | 24 |
| 24 | Petioles >1 mm long; leaflets with l:w ratio mostly <3; bracteoles narrow-elliptic; pods 6–8 mm wide | Bossiaea dasycarpa |
| Petioles ≤1 mm long; leaflets with l:w ratio mostly >3; bracteoles very narrow-oblong; pods 4–5.5 mm wide
Back to 23 | Bossiaea scortechinii |
| 25 | Ovaries and pods hairy at least on margins; prostrate or weakly erect shrubs to c. 0.5 m high; pods thin, with upper margin < 1 mm wide; pod-stipe usually < 3 mm long | 26 |
| Ovaries and pods glabrous (rare hairy, then tall shrubs, flowers entirely yellow, bracteoles fused); usually erect shrubs, >0.5 m high; pods slightly to very thick, with upper margin >1 mm wide; pod-stipe usually >3 mm long
Back to 20 | 28 |
| 26 | Pedicels mostly >6 mm long; ovary and pod with hairs on margins only; calyx hairy; leaflet apiculum usually < 0.5 mm long | 27 |
| Pedicels < 6 mm long; ovary and pod hairy on valves and margins (rare no or few hairs, then calyx glabrous); leaflet apiculum typically > 0.5 mm long
Back to 25 | Bossiaea neoanglica |
| 27 | Upper calyx lobes c. 0.5 mm longer than lower lobes; keel < 6 mm long; style 1–2 mm long | Bossiaea buxifolia |
| Upper calyx lobes 1.5–3 mm longer than lower lobes; keel > 6 mm long; style 2.5–6 mm long
Back to 26 | Bossiaea decumbens |
| 28 | Branchlets compressed, glabrous or sparsely hairy; stipule mirgins often distorted, not membranous | 29 |
| Branchlets terete, usually moderately hairy; stipule margins membranous
Back to 25 | 32 |
| 29 | Stipules mostly > 4 mm long, green; indumentum with hairs 1–2 mm long | Bossiaea stephensonii |
| Stipules to 1.5 mm long, brown; indumentum with hairs generally < 1 mm long, often glabrous or nearly so
Back to 28 | 30 |
| 30 | All or most leaflets with l:w ratio > 2; upper calyx-lobes > ½ the length of calyx-tube; body of pods > 2.5 cm long | Bossiaea heterophylla |
| Leaflets with l:w ratio < 2; upper calyx-lobes < ½ the length of calyx-tube; body of pods < 2.5 cm long
Back to 29 | 31 |
| 31 | Stipules to c. 0.5 mm long, c. as long as broad, with apex pointing in almost the same direction as petiole; wing petals 10 mm long, largely brownish-red; leaves with l:w ratio mostly < 1.3 | Bossiaea rhombifolia |
| Stipules 0.7–1.5 mm long, longer than broad, with apex pointing almost at right angles to petiole; wing petals 6 mm long, largely yellow; leaves with l:w ratio mostly > 1.3
Back to 30 | Bossiaea concolor |
| 32 | Keel 12–25 mm long, exceeding standard by several mm; persistent stamen-tube > 12 mm long; pod-stipe 10–20 mm long | Bossiaea rupicola |
| Keel to c. 10 mm long, not or hardly exceeding standard; persistent stamen-tube < 12 mm long; pod-stipe 4–10 mm long
Back to 28 | 33 |
| 33 | Leaflets ovate, with base asymmetrical; body of pods 15–40 mm long, partitioned internally (SE Queensland near NSW border) | Bossiaea brownii |
| Leaflets c. circular, with base c. symmetrical; body of pods 10–12 mm long, not partitioned internally (NSW)
Back to 32 | Bossiaea oligosperma |
