Ratibida columnifera (Nutt.) Woot. & Standl. - Long-head Coneflower

Ratibida columnifera plant

Family - Asteraceae

Stems - To -1m tall, erect, multiple from base, simple to branching above, herbaceous, scabrous, antrorse strigose, carinate, angled, from taproot.

Ratibida columnifera stem

Leaves - Alternate, deeply pinnatifid, petiolate below, sessile above, to +10cm long, +5cm broad, scabrous, antrorse strigose. Lobes often divided. Ultimate divisions linear to linear-oblong, to 3mm broad, entire, acute.

Ratibida columnifera leaf

Ratibida columnifera leaf

Inflorescence - Single flower head terminating stem. Peduncle naked, to +20cm long, antrorse strigose.

Involucre - Phyllaries typically in two series of long outer bracts and inner series of minute bracts. Outer phyllaries linear-attenuate, to 6mm long, spreading, antrorse strigose. Inner phyllaries ovate, to +1mm long, densely pubescent.

Ratibida columnifera involucreInvolucre (rays removed).

Ray flowers - Sterile. Typically 6, yellow or with brownish-purple and yellow apices, to +2cm long, +1.5cm broad, pubescent below, glabrous above, spreading to reflexed, notched at apex. Achene black, 1.5mm long, 3-sided, pubescent above. Pappus typically absent or a minute crown.

Ratibida columnifera flower

Ratibida columnifera flower

Disk flowers - Fertile. Corolla 5-lobed, purple. Tube to 1.8mm long, glabrous. Achenes white in flower, compressed, 2.5mm long, 1.5mm broad, with some pubescence. Pappus typically absent or a minute crown. Receptacle columnar, 1.5mm in diameter, to -2cm long. Chaff with deep purple spot near apex, equaling or exceeding the achenes, ciliate-margined.

Ratibida columnifera diskDisk close-up.

Flowering - June - September.

Habitat - Prairies, waste ground, disturbed sites, roadsides, railroads.

Origin - Native to U.S.

Other info. - This striking plant is locally common in some parts of the state but is not wild throughout. It is, however, commonly cultivated and will not doubt escape and spread.
The two forms of the plant are shown above. Form columnifera has the completely yellow ligules. Form pulcherrima (DC.) Fern. has the ligules which are purplish-brown with yellow at the apex.
The disk flowers bloom in an indeterminate fashion along the receptacle.
The name "columnifera" means "column producing", and indeed, the flower does have the distinct columnar receptacle.

Photographs taken of Hwy 60 near Van Buren, MO., 6-20-04.


Back