Senecio squalidus

Linnaeus

Sp. Pl. 2: 869. 1753.

Common names: Oxford ragwort
Introduced
Treatment appears in FNA Volume 20. Treatment on page 560. Mentioned on page 548, 561.

Annuals (or perennials), 15–60+ cm (taprooted). Herbage sparsely, unevenly floccose to subglabrous, glabrescent. Stems single (branching distally). Leaves evenly distributed; petiolate (proximal, petioles ± winged); blades obovate to oblong, 4–10 × 2–4+ cm, mostly lyrate-pinnatifid to pinnate, bases tapered, ultimate margins dentate (distal leaves similar, smaller, sessile). Heads (3–) 6–20 in open, cymiform arrays. Calyculi of 4–10+ bractlets (1–2+ mm). Phyllaries (± 13) ± 21, 5–6+ mm, tips black. Ray-florets ± 13; corolla laminae 5–8 mm. Cypselae usually hairy. 2n = 20.


Phenology: Flowering late winter–spring or fall.
Habitat: Disturbed sites (in regions of cool, damp climates)
Elevation: 0–300 m

Distribution

V20-1247-distribution-map.gif

Introduced; N.S., Calif., Europe

Discussion

Senecio squalidus is native in Europe, where it is a common weed. It is apparently established in the San Francisco Bay area, California and has been reported from British Columbia, New Brunswick, and Nova Scotia. It is to be expected elsewhere.

Selected References

None.

Lower Taxa

None.
... more about "Senecio squalidus"
not tailed +, rounded +  and obtuse +
papillate +
scarious +
usually ovate +  and lance-linear +
cymiform +  and open +
indeterminate +  and determinate +
Theodore M. Barkley† +
Linnaeus +
tapered +
4 cm40 mm <br />0.04 m <br /> (10 cm100 mm <br />0.1 m <br />) +
obovate;oblong +
lyrate-pinnatifid to pinnate +
2cm;4cm +
winged;nerved;ribbed +
barbellulate +  and smooth +
white +  and stramineous +
Oxford ragwort +
purplish +, reddish +, white +, ochroleucous +, yellow +  and white rarely reddish +
0.5 cm5 mm <br />0.005 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
angled +, 5-ribbed +, prismatic +  and cylindric +
fertile +  and bisexual +
fertile +  and bisexual +
N.S. +, Calif. +  and Europe +
0–300 m +
hairy +  and glabrous +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Disturbed sites (in regions of cool, damp climates) +
discoid +  and radiate +
indeterminate +
heterogamous +  and homogamous +
glabrescent +, unevenly floccose +  and subglabrous +
each +  and sessile +
0.5 cm5 mm <br />0.005 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
turbinate;campanulate +
distributed +
cauline +  and basal +
erect;recurved +
deltate +
dentate to pinnatifid +  and entire +
2-carpellate +
persistent +
Flowering late winter–spring or fall. +
mostly oblong +  and lanceolate or linear +
0.5 cm5 mm <br />0.005 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
bearing subulate enations +, hairy +  and bristly +
flat;convex +
exalbuminous +
Introduced +
appendaged +  and truncate +
papillate +
Compositae +
Senecio squalidus +
species +
campanulate +
denticulate +  and serrate or toothed +
15 cm150 mm <br />0.15 m <br /> (60 cm600 mm <br />0.6 m <br />) +
shrub +  and subshrub +