Senecio vulgaris L.

Senecio vulgaris plant

Family - Asteraceae

Stems - Multiple from base, to 40cm tall, from thick taproot, arachnoid pubescent when young, glabrescent when mature, branching, herbaceous, erect, purplish in strong sun, slightly ribbed, fistulose.

Senecio vulgaris stemStem.

Leaves - Alternate, sessile to very short petiolate, auriculate and sub-clasping above, pinnately lobed (the lobes rounded at the apex), to +6cm long, 2.5cm broad, reduced upward, sparse arachnoid pubescent to glabrescent. Lobes typically serrate-dentate.

Inflorescence - Compact paniculate or corymbose clusters of many (10-20) flower heads terminating main stems. Peduncles of flower heads sometimes elongating in fruit to +3cm long. Leaves reduced to bracts and subtending each peduncle in the inflorescence.

Involucre - To 8-10mm long(tall), 5-6mm in diameter. Inner phyllaries uniseriate, to 8mm long, 1mm broad, acute to acuminate, sometimes with a black apex. Outer phyllaries short, 2-3mm long, acuminate, black-tipped. Phyllaries spreading in fruit.

Senecio vulgaris involucreInvolucre.

Ray flowers - Absent.

Disk flowers - Flowers yellow at the apex, pale basally, 5-lobed, glabrous, 5mm long, funnelform near the apex. Lobes rounded, erect to spreading, glabrous, .5mm long. Stamens 5, adnate near the apical 1/5 of the corolla tube, included to partially exserted. Anthers yellow-brown, connate around the style, -1mm long. Filaments white, glabrous, -1mm long. Style bifurcate, purplish at the apex (stigma), glabrous. Achenes brown at maturity, 3mm long, -1mm in diameter, linear, terete, 9-nerved, with short retrorse strigose pubescence. The pubescence situated in the grooves between the ribs, silvery-white. Pappus of numerous capillary bristles. Bristles barbellate, to +/-6mm long.

Senecio vulgaris involucreFruiting involucre.

Senecio vulgaris fruitsFruits.

Flowering - June - October.

Habitat - Roadsides, railroads.

Origin - Native to Europe.

Other info. - This little plant is becoming much more common in Missouri than in the past. The fruits are dispersed by the wind helping the plant to thrive and expand its range. This species is easy to identify in the field because of its pinnately lobed leaves, small but numerous flower heads, and purplish stems.
Some species in this genus are used medicinally but many contain pyrrolizidine alkaloids, which can be toxic.

Photographs taken in Salter Path, NC., 3-1-03.