Taxonomy

Senecio vulgaris L., Sp. Pl. 2: 867. 1753.

Common name

Common groundsel, birdseed, chickenweed, old-man-of-spring, swallow

Description

Propagule or dispersal unit is the fruit with pappus. Fertile part 2-3 mm long, 0.3-0.6 mm wide, in side view widest in upper part (obovoid), widest in lower part (ovoid) or widest in the middle, +/- straight or conspicuously curved, the upper (apical) end narrowing, in cross-section round (terete), basal scar (carpopodium) pronounced and well-differentiated or inconspicuous and undifferentiated, central, beak (=thinner sterile stalk between seed and pappus) absent, wings absent, fruit surface light brown or straw, smooth (except at cellular level), with simple straight hairs, thickened margin absent, longitudinal ribs present, (0-)9-11, their surfaces smooth, with no hairs (glabrous).

Pappus type bristles / hairs, pappus elements all +/- similar, up to 5-9.5 mm long, in one row, pappus elements numerous, elements falling off individually, the individual bristles rough / serrated (barbellate), +/- equal width along length, white / translucent.

Notes: The pappus bristles are deciduous and will consequently most likely be missing in most cases when this species is encountered. The fruits of the various Senecio species are very similar. Of the two in this key, S. vulgaris has the slightly larger ones, with the fertile part 2 mm or more as opposed to up to 2 mm. Note, however, that the genus has hundreds of other species that are not covered in the key.

Ecology

Annual herb, fruit wind-dispersed but presumably somewhat limited in distance due to early loss of pappus hairs. Temperate zones, prefers fertile soils. Especially on agricultural land, disturbed or managed forest systems, wasteland, rail- and roadsides, and urban areas.

Native range

Widespread through Europe, northern Africa, and temperate Asia.

Introduced range

Canada, United States, Mexico, Caribbean, Colombia, Ecuador, Chile, Argentina, Kenya, Zambia, Mozambique, Taiwan, Australia, New Zealand.

Past interceptions (Australia): origins

United Kingdom, Spain, Germany, Czech Republic, Hungary, Japan.

Other or unidentified species of the genus also from Canada, United States, Costa Rica, Colombia, Ecuador, Netherlands, Italy, Ethiopia, Tanzania, India, China, Korea, Thailand, Papua New Guinea, Vanuatu, New Caledonia.

Past interceptions (Australia): commodities

New vehicles.

Other or unidentified species of the genus also in/on agricultural machinery, machinery and parts, timber pallets, dried leaves, stone products, cut flowers, nursery stock, seeds for sowing, containers, used tyres, used vehicles, woven baskets.