Family: Asteraceae
Senecio jacobaea
Citation:
L., Sp. Pl. 2:870 (1753).
Synonymy: Not Applicable Common name: Ragwort.
Description:
Biennial subshrub, with a short thick rootstock, sparsely to densely cottony, glabrescent on the oldest parts; stem erect, stout, striate, often purplish-red, branching above the middle; basal leaves petiolate, lyrate, to 20 cm long, withering early; mid-stem leaves oblong-ovate, 8-15 x 3-4 cm, pinnatisect, the lobes irregularly toothed or lobed, sessile, stem-clasping.
Inflorescence a congested corymbose panicle of numerous capitula; involucre campanulate, 4-5 x 3.5-4 mm, bracts 11-13, abruptly narrowed c. 1 mm below the ciliolate apices; calyculus of 3-5 finely tapered bracteoles; ray florets 10-15; ligules of small heads c. 4 x 1.5 mm, of larger heads 6-10 x 1-1.8 mm; disk florets c. 40.
Achenes 1.8-2 mm long, plump, brown, those of the ray florets glabrous, those of the disk florets with short appressed hairs; pappus uniform, deciduous.
Published illustration:
Lamp & Collett (1976) Field guide to weeds in Australia, p. 284.
Distribution:
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Occurs in pasturages, along roadsides, and in dry sclerophyll woodlands.
S.Aust.: SL. Vic.; Tas. New Zealand, United States (California); native of Europe, widely adventive.
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Conservation status:
native
Flowering time: Dec. — May.
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SA Distribution Map based
on current data relating to
specimens held in the
State Herbarium of South Australia
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Biology:
No text
Taxonomic notes:
Apparently first collected in South Australia in 1954, but present in Tasmania as early as 1919 and widespread over much of the island. A noxious weed poisonous to livestock by cumulative liver damage.
Author:
Not yet available
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