1	"Capitula radiate, i.e. outer florets ligulate, female; inner florets tubular, bisexual (but ligules much reduced or vestigial in S. glossanthus, S. halophilus and S. productus)"	2
1	"Capitula non-radiate, outer florets female or bisexual; inner florets bisexual"	23
2	"Scrambling or semi-climbing perennial to c. 5 m high; leaves rhombic to ovate (often broadly toothed), 3–5 cm long, rather fleshy; garden-escape"	"Senecio angulatus"
2	"Habit and foliage not as above"	3
3	"Ligules rich purple (rarely white); coastal weed with pinnatisect foliage"	"Senecio elegans"
3	"Ligules yellow"	4
4	"Ligules minute, to 2 mm long"	5
4	"Ligules conspicuous, at least 3 mm long"	7
5	"Involucral bracts 12 or 13 in majority of capitula; female florets 8–13; ligule vestigial; cypselas of female florets 3–6 mm long, slightly lageniform"	"Senecio productus subsp. productus"
5	"Involucral bracts 7–10, or occasionally to 13, in a majority of capitula; female florets predominantly 4–8; ligule vestigial or to 2 mm; cypselas of female florets 2–3.5 mm long, not lageniform"	6
6	"Involucre 3.5–6 mm long; calycular bracteoles 0.2–0.5 mm wide; mature receptacle 1–2(–2.5) mm diam.; ligules generally exceeding involucre; hairs on cypselas of bisexual florets 0.05–0.15 mm long, barely exceeding pappus ring"	"Senecio glossanthus"
6	"Involucre 5–7 mm long; calycular bracteoles 0.5–1 mm wide; mature receptacle mostly 2–3.5 mm diam.; ligules not exceeding involucre; hairs on achenes of bisexual florets 0.2–0.3 mm long, clearly exceeding pappus ring"	"Senecio halophilus"
7	"Involucral bracts fused for at least half their length prior to fruit ripening; bracteoles absent; ligules relatively large (to c. 2 cm long); glaucous annual of far north-west"	"Senecio gregorii"
7	"Involucral bracts fused for less than half their length (usually almost or entirely free); bracteoles usually present"	8
8	"Leaves white-tomentose beneath"	9
8	"Leaves glabrous to sparsely pubescent beneath (sometimes mealy-white in rare S. behrianus from northern Victoria)"	11
9	"Larger leaves at least 25 mm wide, those at least of main axis with stem-clasping bases; north-east only and rare"	"Senecio garlandii"
9	"Leaves to c. 20 mm wide, without stem-clasping bases"	10
10	"Involucre cylindric with 9–12 bracts; leaves entire or shallowly toothed"	"Senecio linearifolius"
10	"Involucre rather broadly campanulate with 18–22 bracts; at least the lower leaves with several deeply incised, forward-pointing teeth"	"Senecio pterophorus"
11	"Involucral bracts and bracteoles sparsely to densely covered with black glandular papillae; cypselas glabrous, blackish with broad, somewhat wrinkled ribs"	"Senecio vagus"
11	"Involucral bracts and bracteoles not glandular; cypselas not as above"	12
12	"Cypselas of ray florets c. 1 mm longer than those of disc florets; bracteoles with intense purple pigmentation in distal half to one third"	"Senecio condylus"
12	"Cypselas of ray florets equal or hardly longer than those of disc florets, or if clearly longer then bracteoles without intense purple pigmentation"	13
13	"Leaves pinnatifid to bipinnatisect (primary lobes divided at least halfway to midrib)"	14
13	"Leaves entire or with shallowly toothed or lobed margins"	17
14	"Involucre 7–10 mm long; cypselas evenly and densely white-pubescent with persistent pappus; far north-west only"	"Senecio platylepis"
14	"Involucre less than 7 mm long; cypselas minutely hairy in rows or glabrous"	15
15	"Inflorescence with numerous (c. 30–200) capitula; bracteoles of most capitula mostly fewer than 5; first-year leaves forming a basal rosette; cypselas dimorphic- those of ray florets glabrous, those of disc florets with lines of short hairs"	"Senecio jacobaea"
15	"Inflorescence of up to c. 30 capitula; bracteoles of most capitula mostly more than 5; leaves not initially rosetted; cypselas uniform, either glabrous or hairy"	16
16	"Leaves with 0–4(–6) marginal points per side, not developing strap-like basal segments; mid-stem leaves with rachis mostly greater than 0.8 mm wide with length:width ratio less than 15 when dried; cypselas 1.8–2.8 mm long; mostly in north-west"	"Senecio spanomerus"
16	"Leaves with 0–40 marginal points per side, sometimes developing strap-like basal segments; mid-stem leaves with rachis less than 0.8 mm wide with length:width ratio greater than 15 when dried; cypselas (1.6–)2–4.5 mm long; mostly in south and east"	"Senecio pinnatifolius"
17	"Involucre 9–12.5 mm long; inflorescence often a single capitulum; decumbent to suberect rhizomatous perennial of sandy coasts"	"Senecio spathulatus"
17	"Involucre less than 8 mm long; inflorescence usually of several capitula"	18
18	"Involucral bracts 13 or fewer; ligulate florets to 6 mm long"	19
18	"Involucral bracts more than 13 in at least most capitula; ligulate florets (5–) 6–15 mm long"	20
19	"Rhizomatous, grey-leaved shrub, not or hardly aromatic; inflorescence of 1–few capitula; rare northern shrub of heavy ground prone to inundation"	"Senecio behrianus"
19	"Non-rhizomatous herb or shrub, strongly aromatic; inflorescence corymbose, of c. 20–200 capitula; widespread, mainly in wet forests"	"Senecio linearifolius"
20	"Cypselas densely papillose-pubescent all over; pappus persistent; north-western and exceedingly rare (possibly extinct) in Victoria"	"Senecio murrayanus"
20	"Cypselas glabrous or shortly hairy in longitudinal rows; pappus deciduous"	21
21	"Bracteoles not or barely overlapping base of involucre; neither bracts nor bracteoles conspicuously black-tipped; cypselas 1.5–2.2 mm long, 0.3–0.5 mm diam."	"Senecio madagascariensis"
21	"Bracteoles overlapping base of involucre; both bracts and bracteoles conspicuously black-tipped; cypselas (1.6–)1.8–4.5 mm long, 0.5–0.8 mm diam."	22
22	"Leaves with 0–4(–6) marginal points per side, not developing strap-like basal segments; mid-stem leaves rachis mostly greater than 0.8 mm wide with length:width ratio less than 15 when dried; cypselas 1.8–2.8 mm long; mostly in north-west"	"Senecio spanomerus"
22	"Leaves with 0–40 marginal points per side, sometimes developing strap-like basal segments; mid-stem leaves rachis less than 0.8 mm wide with length:width ratio greater than 15 when dried; cypselas (1.6–)2–4.5 mm long; mostly in south and east"	"Senecio pinnatifolius"
23	"Florets all bisexual, prominently exserted beyond involucre at anthesis"	24
23	"Outer florets female, inner florets bisexual, often barely exserted beyond involucre at anthesis"	30
24	"Involucral bracts 18–23, usually prominently black-tipped; annual weed of cultivation"	"Senecio vulgaris"
24	"Involucral bracts no more than 14, not black-tipped"	25
25	"Capitula with less than 25 florets; corollas of outer florets exceeding involucral bracts by 2–5 mm"	26
25	"Capitula with more than 25 florets; corollas of outer florets level with or exceeding involucral bracts by up to 2 mm"	29
26	"Leaves of major branches to 15 mm wide; reticulate venation of leaves obscure"	27
26	"Leaves of major branches to 50 mm wide; reticulate venation clearly defined on one or both surfaces"	28
27	"Margins of leaves of the major branches denticulate, dentate or lobate, flat or finely recurved; bracteoles with length:width ratio mostly greater than 3; peduncles commonly somewhat woolly at anthesis"	"Senecio lanibracteus"
27	"Margins of leaves of the major branches entire (margin of stem leaves may be dentate), revolute; bracteoles with length:width ratio mostly less than 2; peduncles glabrous at anthesis"	"Senecio cunninghamii"
28	"Plant not glaucous; mid-branch leaves tapering strongly to a petiole-like proximal portion 1–4 cm long, auricles absent or small, lower surface  ± completely obscured by indumentum"	"Senecio hypoleucus"
28	"Plant often glaucous; mid-branch leaves not tapering strongly to a petiole-like proximal portion, auricles commonly well-developed and usually moderately stem-clasping; lower surface mostly glabrous or sparsely indumented,  rarely moderately obscured by indumentum"	"Senecio odoratus"
29	"Leaves densely woolly on both surfaces,  inflorescence branchlets, peduncles and bracts densely woolly; bracteoles greater than 4 mm long"	"Senecio helichrysoides"
29	"Leaves densely appressed woolly on lower surface only, inflorescence branchlets, peduncles and bracts sparsely woolly; bracteoles less than 4 mm long"	"Senecio georgianus"
30	"Female florets rays without lobes or ligules; cypselas with hairs that exceed the pappus ring; inflorescence of 1–20 capitula"	31
30	"Female florets disc florets with 2–5 lobes; cypselas glabrous or with short papillose hairs; inflorescence of 10 to several hundred capitula"	32
31	"Involucral bracts 12 or 13 in majority of capitula; female florets 8–13; cypselas of female florets 3–6 mm long, slightly lageniform"	"Senecio productus subsp. productus"
31	"Involucral bracts 7–10, or occasionally to 13, in a majority of capitula; female florets predominantly 4–8; cypselas of female florets 2–3.5 mm long, not lageniform"	"Senecio halophilus"
32	"Cypselas glabrous, lustrous"	33
32	"Cypselas with papillose hairs or if glabrous then not lustrous"	34
33	"Stem creeping to erect, renewed annually from a short rhizome; subalpine"	"Senecio extensus"
33	"Stem erect, not renewed from a rhizome; lowland swamps"	"Senecio psilocarpus"
34	"Involucres 2.8–5 mm wide in fresh material two thirds of the distance along the involucre from the base, all or most comprising 16–25 bracts"	35
34	"Involucres 1.0–3.0 mm wide, comprising 7–14 bracts"	36
35	"Cypselas lageniform, 3.0–6.0 mm long"	"Senecio macrocarpus"
35	"Cypselas cylindric, 2.0–3.0 mm long"	"Senecio squarrosus"
36	"Leaves conspicuously retrorsely lobed"	"Senecio runcinifolius"
36	"Leaves unlobed, or if lobed, segments not conspicuously retrorse"	37
37	"Capitula with up to 50% of florets female or at least with only female structures emergent from corolla tube and reduced corolla lobes"	"Senecio interpositus"
37	"Capitula with 70–80% of florets female, very rarely with 50% of florets female"	38
38	"Stem creeping to erect, renewed annually from a short rhizome; subalpine"	"Senecio lageniformis"
38	"Stem erect, not renewed from a rhizome; widespread"	39
39	"Leaves broadest at the base, where clustered, becoming wider spaced and narrower up the stem, entire or occasionally with 1 or 2 lobes per side in proximal half, with short, multicellular flattened hairs"	40
39	"Leaves usually broadest throughout the midstem, not clustered at the base and more or less evenly spaced and sized throughout the midstem, entire to sub-pinnatisect, with or without short, multicellular flattened hairs"	43
40	"Lower stem bearing spreading multicellular flattened hairs; secondary roots usually slightly tuberiform"	"Senecio prenanthoides"
40	"Lower stem without spreading multicellular flattened hairs; secondary roots never tuberiform"	41
41	"Cypselas 3.0–4.0 mm long; involucre 8.5–12.0 mm long"	"Senecio dolichocephalus"
41	"Cypselas 2.0–3.0 mm long; involucre 5.0–7.5 mm long"	42
42	"Capitula with 12–25 florets; bisexual florets 5–6.0 mm long; pappus 4.5–6.0 mm long"	"Senecio microbasis"
42	"Capitula with 30–45 florets; bisexual florets 6–7.0 mm long; pappus 6.0–7.5 mm long"	"Senecio phelleus"
43	"Leaves grey on both surfaces due to a woolly tomentum, elliptic"	"Senecio gunnii"
43	"Leaves green on at least one surface or if grey on both surfaces then linear"	44
44	"Axils with precociously developing leafy growth above mid stem; leaves on both surfaces glabrous or nearly so; Gippsland river valleys"	"Senecio diaschides"
44	"Axils without precociously developing leafy growth or if present then leaves clearly hairy; widespread"	45
45	"Stems glabrous or with cottony hairs; leaves entire, rarely lobate with 1–3 segments in proximal half; cypselas usually lageniform, rarely cylindric"	46
45	"Stems, at least basally, with sparse to dense short multicellular flattened hairs; leaves entire to sub-pinnatisect; cypselas cylindric, narrow-ellipsoid, rarely slightly lageniform"	49
46	"Plants multistemmed and much-branched in lower half in its first season; stem leaves with bidentate auricles"	"Senecio glabrescens"
46	"Plants usually not both multistemmed and branched in lower half in its first season; stem leaves with auriucles absent or present only above mid stem and then entire"	47
47	"Taproot well-developed; secondary roots hardly fleshy; stems moderately to densely appressed cottony or woolly (sometimes glabrescent with age); mid stem leave narrow-linear, length:width ratio greater than 20"	"Senecio quadridentatus"
47	"Taproot slender, inconspicuous; secondary roots fleshy; stems glabrous or only sparsely cottony; mid stem leaves very narrow-elliptic to linear (usually distinctly tapering to each end), length:width ratio less than 20"	48
48	"Mid stem leaves less than 15 mm wide, length:width ration greater than 15; lower surface of leaves lacking coarse hairs; involucre 5–8 mm long; cypselas 2.5–4.5 mm long"	"Senecio campylocarpus"
48	"Mid stem leaves greater than 15 mm wide, length:width ratio less than 10; lower surface of leaves frequently with short flattened, multicelled hairs ; involucre 7–9 mm long; cypselas 4–6 mm long"	"Senecio longicollaris"
49	"Leaves usually entire; short, multicellular, flattened hairs sparse on stems and leaves"	"Senecio minimus"
49	"Leaves usually regularly dissected more than a quarter of the distance to midrib; short, multicellular, flattened hairs scattered to moderately dense on stems and leaves"	50
50	"Leaves pinnatisect to sub-bipinnatisect, usually including upper leaves"	"Senecio bathurstianus"
50	"Leaves not dissected deeper than deeply lobate or if ever pinnatisect then upper stem leaves usually not pinnatisect"	51
51	"Florets 40–60 per capitulum; cypselas 2.5–3 mm long; involucral bracts black at apex"	"Senecio nigrapicus"
51	"Florets less than 40 per capitulum or if greater than 40 then either cypselas less than 2.5 mm or involucral bracts not black at apex"	52
52	"Peduncles and bracteoles, and often lower surface of upper stem leaves, cobwebby to woolly at anthesis"	"Senecio glomeratus"
52	"Peduncles and bracteoles ± glabrous or sparsely hairy at anthesis, lower surface of upper stem leaves  never cobwebby or woolly"	53
53	"Stems and lower surface of leaves often intensely purple; segments of lower leaves roughly semicircular, perpendicular to the midrib"	"Senecio picridioides"
53	"Stems and lower surface of leaves mostly green, sometimes slightly to moderately purple; segments of lower leaves triangular, oblong or obovate, angled away from the stem"	54
54	"Cypselas 3.0–4.0 mm long, pale olive-brown, glabrous"	"Senecio niveoplanus"
54	"Cypselas 1.5–3.2 mm long, tan, brown or red-brown, glabrous or with papillose hairs"	55
55	"Florets 18–45; involucral bracts usually 11–14"	56
55	"Florets 12–20; involucral bracts usually 7–10"	57
56	"Lower half of stems sparsely to moderately covered with flattened multicellular hairs, becoming rather sparse above mid stem; apex of involucral bracts with a small black spot less than 0.5 mm long; cypselas red-brown"	"Senecio hispidulus"
56	"Lower half of stems densely covered  with flattened multicellular hairs, usually remaining frequent in upper stem region and present on inflorescence branches; apex of involucral bracts marked with a purple zone c. 1 mm long; cypselas tan or chocolate-brown"	"Senecio hispidissimus"
57	"Primary roots inconspicuous; secondary roots fleshy; leaves with a continuous medial band of lamina roughly oblong and the distal centimetre of leaves commonly with an oblong section 2–8 mm long; cypselas with a length:width ratio of c. 4–5"	"Senecio distalilobatus"
57	"Primary roots well-developed; secondary roots not fleshy; leaves with the continuous medial band of lamina somewhat elliptic and the distal centimetre of leaves roughly triangular; cypselas with a length:width ratio of c. 6–7"	"Senecio biserratus"