Family – Asteraceae
Stems – To 2m tall, erect, from fibrous roots and rhizomes, purplish, carinate, simple or branching near apex, herbaceous, fragrant, glabrous.
Leaves – Alternate, petiolate below to sessile above, to -30cm long, 15-16cm broad, deeply pinnatifid to pinnately divided. Lobes serrate, punctate, glabrous. Leaf tissue on rachis also lobed (toothed) and punctate. Leaves fragrant.
Inflorescence – Dense terminal corymbiform arrangement of flower heads. Peduncles glabrous.
Involucre – 1cm in diameter, 5-6mm tall, cupulate. Phyllaries imbricate, 4mm long, -2mm broad, glabrous, with scarious margins, blunt to obtuse at apex and often erose.
Ray flowers – Absent.
Disk flowers – Disk to +/-1cm broad. Corolla tube whitish-yellow, glabrous, +?-2.3mm long, 5-lobed. Lobes acute, .2mm long, yellow. Stamens 5, adnate at base of corolla tube. Anthers yellow, .8mm long, connate around style near apex of corolla tube, included. Style bifurcate, slightly exserted. Achene white in flower, 1mm long, glabrous, 5-angled. Pappus absent or a minute crown. Receptacle conic.
Photographic Location: Sycamore Ridge Ranch in Middle TN.
Flowering – July – September.
Habitat – Meadows, fence rows, prairie margins, fields, roadsides, railroads, cultivated.
Origin – Native to Eurasia.
Other info. – Tansy has been used in the past as a remedy for many ailments. The plant is quite toxic and causes abortions and even death in most mammals.
Grown as an ornamental, the plant is quite striking but has a tendency to get “leggy” and fall over at maturity. Hybrids and cultivars exist which have better growing habits.