Ratibida columnifera (Nutt.) Woot. & Standl. - Long-head Coneflower
Family - Asteraceae
Stems - To -1m tall, erect,
multiple from base, simple to branching above, herbaceous, scabrous, antrorse
strigose, carinate, angled, from taproot.
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.
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.
Involucre (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.
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.
Disk 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.
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