Senecio L.

Volume IV (1988) - Flora of New Zealand Naturalised Pteridophytes, Gymnosperms, Dicotyledons

SENECIO L.

Annual, biennial, or perennial herbs, shrubs, trees or climbers. Lvs simple, entire to pinnately or palmately toothed, lobed, or compound, alternate. Capitula in corymbs, panicles, or solitary; involucral bracts in 1 row, usually with shorter supplementary bracts subtending base of involucre. Receptacle ± flat or convex; scales 0. Outer florets ♀ and ligulate, ♀ and tubular, or ⚥ and tubular; ligules usually yellow, sometimes white, pink, orange, or mauve to purple; inner florets ⚥. Achenes usually ± cylindric, 5-10-ribbed, often with short antrorse hairs, sometimes glabrous, rarely dimorphic with ray achenes glabrous and disc achenes hairy; pappus present but sometimes caducous, denticulate, simple or rarely plumose.

Key

Glabrous scandent or scrambling herbs

Glabrous or hairy herbs or shrubs, sometimes prostrate or ascending but not scandent

Lf teeth with flat or concave sides; petioles often with small auricles at base; ray florets 0

10. *mikanioides

Lf teeth with convex sides; petioles always without auricles; ray florets (4)-5

1. *angulatus

Capitula discoid

Capitula radiate

Flowering capitula 4-15 mm diam.

Flowering capitula 1-3 mm diam.

Lvs entire, succulent, subterete; corolla white

*serpens ζ

Lvs serrate to lobed, at most fleshy, strongly vertically compressed; corolla yellow

Prostrate or ascending perennial herb, becoming woody toward base, glabrous, or sparsely hairy especially when young; supplementary bracts < 11

Erect or straggling soft annual or short-lived perennial, sparsely to moderately hairy and becoming glabrous or remaining hairy on undersurface of lvs, if almost glabrous, then supplementary bracts 8-21

Lvs deeply 1-pinnatifid to 1-pinnate, (12)-15-30 mm long; achenes with few scattered hairs between ribs; plant prostrate, ascending only at tips

21 hauwai

Lvs serrate or pinnately lobed, sometimes pinnatisect near infl., 20-80-(90) mm long; achenes sparsely to densely hairy between ribs; plant prostrate to almost erect

19. glaucophyllus subsp discoideus

Flowering capitula 2-3-(4) mm diam.; plant 10-50 cm tall; N., S., St., Ch., C.

14. *vulgaris

Flowering capitula 5-15 mm diam.; plant often > 50 cm tall; A.

28. radiolatus subsp antipodus

Involucral bracts (13)-18-21; supplementary bracts 8 -21, black-tipped, glabrous or with few scattered hairs

14. *vulgaris

Involucral bracts usually 5-14, very rarely up to 16; supplementary bracts usually 0-7, or if 8-14, then with woolly hairs, and green or with dark tips

Mid cauline lvs deeply pinnatifid with linear to lanceolate, entire, irregularly-toothed or again pinnatifid segments; achenes with 1 row of hairs on or beside ribs

3. *bipinnatisectus

Mid cauline lvs entire to 1-pinnatifid with lanceolate to oblong, ovate or obovate, toothed but not usually pinnatifid segments, if segments narrow or lvs 2-pinnatifid then achenes evenly hairy or hairs in 1-6 rows between ribs

Involucral bracts mostly 5-9

Involucral bracts mostly 10-14

Mid cauline lvs usually pinnately lobed with the segments irregularly serrate or dentate; achenes 2.5-2.8 mm long

16. biserratus

Mid cauline lvs evenly, finely dentate, remotely dentate or shallowly 1-pinnatisect; achenes 1.5-2.8 mm long

Mid cauline lvs remotely dentate to shallowly 1 -pinnatisect

5. *diaschides

Mid cauline lvs evenly, finely dentate

Involucral bracts (7)-8-(10); mid cauline lvs narrow-elliptic to narrow-lanceolate; achenes 1.8 -2 mm long, with hairs on ribs

26. minimus

Involucral bracts 5-7-(8); mid cauline lvs elliptic; achenes 2-2.5 mm long, with hairs in grooves between ribs

23. kermadecensis

Lvs hispid with jointed hairs on lower surface, and tuberculate-based or slender jointed hairs on upper

Lvs glabrous, sparsely to moderately hairy, or lanate, but not hispid

Achenes 1.5-1.8 mm long, with hairs confined to grooves between ribs

22. hispidulus

Achenes (2)-2.2-2.6-(3) mm long, usually ± evenly covered in hairs

30. scaberulus

Mid cauline lvs sparsely to densely white-lanate on lower surface, or if sparsely hairy, then lanate at base of involucre

Mid cauline lvs glabrous or sparsely to moderately hairy but not lanate; involucre glabrous or sparsely hairy but not lanate

Involucral bracts (5.5)-6-9 mm long; mid cauline lvs entire or remotely denticulate, moderately to densely white-lanate on lower surface

27. quadridentatus

Involucral bracts (4)-4.5-6 mm long; mid cauline lvs pinnately lobed to remotely denticulate, or rarely entire, glabrous to densely white-lanate on lower surface

Mid cauline lvs pinnately lobed or incised with entire or few-toothed segments; supplementary bracts 8-14; achenes 1.2-1.6 mm long

20 glomeratus

Mid cauline lvs usually remotely denticulate, rarely entire; supplementary bracts 3-5-(6); achenes c. 2.5 mm long

18. dunedinensis

Involucral bracts 4.5-5.5 mm long; mid cauline lvs remotely denticulate to shallowly 1-pinnatisect, rarely entire

Involucral bracts 5.5-8 mm long; mid cauline lvs shallowly pinnately lobed and denticulate to lyrate- pinnatifid or 1-2-pinnatifid

Achenes with hairs mostly on ribs, sometimes evenly hairy; mid cauline lvs not amplexicaul at base

18. dunedinensis

Achenes with hairs in grooves between ribs; mid cauline lvs often amplexicaul and deeply 1-3-fid at base

5. *diaschides

Lvs sparsely to moderately hairy especially on lower surface; achenes densely hairy between ribs; outer florets often with inconspicuous ligules

13. *sylvaticus

Lvs almost glabrous or with few scattered hairs; achenes glabrous or with 1-3 rows of hairs between ribs; ligules always 0

32. wairauensis

Ligules purple, mauve, mauve-pink, pale to deep pink or white

Ligules yellow

Annual; lower cauline lvs lyrate-pinnatifid to pinnatisect, petiolate; involucral bracts 13-14

6. *elegans

Perennial; lower cauline lvs serrate, apetiolate; involucral bracts 19-23

7. *glastifolius

Capitula 2-3 mm diam.; ligules 0.5-2 mm long, recurved; supplementary bracts 3-6

13. *sylvaticus

Capitula c. 4 mm diam. or greater; ligules 1-24 mm long, but if < 3 mm long then supplementary bracts usually > 6

Lamina ± orbicular, minutely denticulate and shallowly lobed; venation palmate

11. *petasitis

Lamina longer than broad, entire or dentate to serrate, or pinnatisect or 1-pinnate; venation pinnate or obscured by hairs

Mature mid cauline lvs moderately to densely hairy or lanate, at least below

Mature mid cauline lvs glabrous, sparsely hairy or glandular

Erect or straggling, fleshy, short-lived perennial herb; lvs becoming glabrous or sparsely hairy on upper surface

Shrub or prostrate to ascending perennial herb woody toward base, not fleshy; lvs remaining moderately to densely hairy on upper surface

Ligules 1.5-4-(6) mm long; Ch.

28. radiolatus subsp radiolatus

Ligules (3)-4.5-9-(10) mm long; South Id and islands near the coast of mainland N.Z.

31. sterquilinus

Peduncles and involucral bracts almost glabrous

15. banksii

Peduncles and involucral bracts densely lanate

Lvs entire or obscurely serrate except at 3-fid or dentate apex; ligules c. 20 mm long

*crassiflorus ζ

Lvs lyrate-pinnatifid to 2-3-pinnatisect; ligules 3-7 mm long

4. *cineraria

Ray florets 5-6; achenes 1.2-1.4 mm long; lvs linear to lanceolate, entire or remotely denticulate, 60-120 mm long

9. *linearifolius

Ray florets 7-23; achenes 1.4-3.5 mm long; lvs distinctly serrate or dentate to more deeply dissected, or if narrow and few-toothed or entire, then < 60 mm long, ray florets 8 or more and achenes > 2.8 mm long

Erect biennial or perennial herbs; cauline lvs lyrate- pinnatifid to 1-pinnate with segments again 1 -2-pinnatisect, membranous; uppermost lvs pinnatisect

Annual or short-lived perennial herbs mainly of coastal sites, or prostrate, ascending or erect perennials usually somewhat woody toward base; cauline lvs simple and entire to 2-pinnatisect, membranous or fleshy; uppermost lvs entire, serrate, lobed or pinnatisect

Infl. usually flat-topped, dense; disc achenes moderately hairy; segments of mid cauline lvs 1-2-pinnatisect

8. *jacobaea

Infl. diffuse; disc achenes usually glabrous, rarely innermost sparsely hairy; segments of mid cauline lvs once-toothed

2. *aquaticus

Annual or short-lived perennial herbs mainly of coastal sites; lvs usually fleshy, entire or with 1-6-(8) teeth or segments on each side (very rarely with up to 15 small teeth, then lvs fleshy and involucral bracts 18-23)

Perennial herbs, usually becoming woody toward base; lvs membranous or subfleshy, with (4)-5-20 or more teeth on each side; involucral bracts (10)-12-22

Involucral bracts (13)-18-23, if fewer than 18, then ray florets 13-23 and involucral bracts 6 -11 mm long

Involucral bracts 10-15-(16); ray florets 7 -13-(22); involucral bracts 2.5-9 mm long

At least some lvs usually entire, others toothed or pinnatisect, glabrous or with scattered hairs on mid vein below and ciliate at base, 2-10-(15) mm wide

12. *skirrhodon

All lvs pinnatisect or pinnately lobed, sparsely to moderately hairy especially on lower surface and when young, (10)-20-80 mm wide

31. sterquilinus

Ligules (1)-2-7-(9) mm long; involucral bracts 4 -6.5 mm long

24 lautus

38A

Lvs narrow-ovate, elliptic or lanceolate, at least some lvs usually deeply pinnatifid with narrow lobes

var lautus

Lvs ± oblong, all irregularly serrate or lobed

var esperensis

Ligules 1-4 mm long; involucral bracts (5)-5.5-9 mm long; mid cauline lvs pinnatifid with broad segments or remotely dentate

Plant erect; lower lvs elliptic and serrate; mid cauline lvs oblanceolate to linear-oblong, remotely denticulate; ligules 1-2 mm long

25. marotiri

Plant prostrate to ascending; lvs oblong to elliptic or obovate, usually pinnatifid with broad few-toothed segments; ligules (1)-2-4 mm long

17. carnosulus

Lvs 20-80-(90) × (4)-12-25-(30) mm, with (4)-5-9-(11) teeth or segments on each side

19. glaucophyllus

Lvs 40-180-(210) × (15)-20-80-(90) mm, with (7)-10-20 or more teeth or segments on each side

Lower lvs cuneate, quite glabrous; achenes with broad ribs much wider than grooves; ray florets 7 -9-(10); plant evergreen

15. banksii

Lower lvs long-cuneate, glabrous or sparsely hairy and glandular; achenes with narrow ribs ± = grooves; ray florets 7-14; plant summergreen

29. rufiglandulosus

c. 1500 spp., cosmopolitan. Native spp. 18, naturalised 16.

Senecio is one of the largest genera of flowering plants. The genus as defined here differs from Allan's (1961) circumscription in 2 respects: firstly, Australasian spp. previously treated in Erechtites are placed in Senecio following Belcher, R. O., Ann. Missouri Bot. Gard. 43 : 1-85 (1956). Two N. American spp. of Erechtites sens. strict. are naturalised in N.Z. Drury, D. G., New Zealand J. Bot. 12 : 513-540 (1974), provided a key to, and excellent illustrations of, all erechtitoid N.Z. senecios and his treatment is followed here. Secondly, the segregation from Senecio of cacalioid genera is accepted (Nordenstam 1978, op. cit., see notes under key to genera of Senecioneae).

Within Senecio as circumscribed here, the greatest taxonomic problems are in the S. lautus and S. glaucophyllus groups. An attempt has been made to correct some of the more obvious difficulties by making new combinations and describing new spp. [Sykes, W. R., New Zealand J. Bot. 25 : 611-613 (1987); Webb, C. J., in Connor, H. E. and Edgar, E., ibid. 25 : 148 (1987)]. Ornduff, R., Trans. Roy. Soc. N.Z. 88 : 63-77 (1960), also considerably advanced our understanding of this group of spp., but the relationship of N.Z. and Australian plants assigned to S. lautus remains unclear [Ali, S. I., Austral. J. Bot. 12 : 282-291 (1964), ibid. 17 : 161-176 (1969)], and difficulties remain at intraspecific level in S. colensoi, S. glaucophyllus and S. rufiglandulosus.

Lf shape and hairs are important in identification (Fig. 30 illustrates lvs of erechtitoid spp.); lf descriptions, unless otherwise stated, apply to the lower to mid cauline lvs which are still present at flowering and fruiting. The number of involucral bracts, with modal values of c. 7-8, 13, or 21, is a useful character; achene shape, length and hair distribution aid identification of the erechtitoid spp.

Fig. 30. Lower cauline lvs of erechtitoid senecios. A S. quadridentatus; B S. dunedinensis; C S. diaschides; D S. minimus; E S. kermadecensis; F-G S. glomeratus, F mainland form, G Chatham Is form; H S. biserratus; I S. hispidulus; J S. scaberulus; K-M S. wairauensis, K upland South Id form, L normal form, M southern form; N-O S. bipinnatisectus, N setose form, O normal form. © All rights reserved. [Image: 4X4N]

Senecio L.

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