Coreopsis palmata Nutt.

Coreopsis palmata plant

Family - Asteraceae

Stems - From a small crown and rhizomes, single or multiple from the base, herbaceous, erect, to -1m tall, simple to branching, green with light green vertical striations, somewhat carinate or not, somewhat angled in the upper 1/2, mostly glabrous or with a few hairs at the nodes, +/-3mm in diameter.

Coreopsis palmata stem

Leaves - Opposite, sessile, decussate, 3-5-lobed in the apical 1/2, shaped like a turkey foot, deep green above and below, sometimes with light green around the midvein abaxially, to +/-6cm long, antrorse strigillose above and below and on margins. Lobes 3-6mm broad, entire, typically with a minute whitish tip (use a lens to see). The central lobe typically longer than the lateral lobes. All the main veins of the leaf coming from the very base of the leaf. Leaves reduced to bracts in the inflorescence.

Coreopsis palmata leaves

Inflorescence - Single pedunculate flower head terminating each stem. Some flowers axillary from the upper leaf axils. Peduncle typically naked, glabrous, slightly expanded just below the involucre.

Involucre - Biseriate. Outer series of +/-12 phyllaries. Phyllaries subulate-linear, entire, ascending, 6-7mm long, 2mm broad, rounded at the apex, with sparse strigose-ciliate margins. Inner phyllaries yellow-brown, bent outward in the apical 1/3, glabrous, 4-5mm broad, 7-9mm long, oblanceolate to spatulate, rounded to subacute at apex, with brown vertical striations, green at base.

Coreopsis palmata involucreInvolucre.

Ray flowers - Sterile, 8-10 per flower head. Ligule yellow, 2-3cm long, +/-1cm broad, mostly glabrous or with a few hairs on the veins below, with 2 impressed veins near the base, 3-toothed at the apex, elliptic-oblong. Corolla tube greenish, +/-3mm long, with sparse multicellular trichomes. The trichomes pilosulous. Achenes compressed, brown at maturity, glabrous, with scarious margins, truncate apically and basally, to 5mm long. Pappus none.

Disk flowers - Disk -1cm broad. Corolla tube 5mm long, yellow, 5-lobed, constricted at the base and opaque, expanded in the apical 1/2 and translucent yellow, with a few multicellular trichomes at the apex of the constriction. Apical 1/2 with 5 brown vertical nerves. Lobes erect, acute, -1mm long. Stamens 5, adnate at the base of the expanded portion of the corolla tube. Filaments yellow, glabrous, +2mm long, with a visible midvein, slightly compressed. Anthers brown-purple, 2-2.2mm long, partially exserted, connate around the style. Style bifurcate, exserted beyond the anthers, yellow in the apical 1/2, white basally, glabrous. Stigmas short, yellow, broadly lanceolate, +/-1mm long. Achenes as in the ray flowers but often thinner. Pappus none. Receptacle flat. Chaff linear, translucent, 7-9mm long, with brown vertical striations, slightly expanded at the apex, .3mm broad or less.

Coreopsis palmata flowers

Flowering - May - July.

Habitat - Prairies, glades, fallow fields, rocky open woods, thickets, roadsides.

Origin - Native to U.S.

Other info. - This striking species is a common roadside plant in the Ozarks in early summer. It is usually on of the first members of its genus to bloom. The plant is easy to ID in the field because of its parted, opposite leaves. It would make an easy garden subject and should be cultivated more.

Photographs taken off Hwy 106, Shannon County, MO., 6-6-03.


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