Euthamia graminifolia (L.) Nutt.

Common Flat-Topped Goldenrod

Euthamia graminifolia plant

Family - Asteraceae

Stems - To -1m tall, branching in upper 1/2, herbaceous, erect, short pubescent, minutely winged (ribbed) from leaf bases, from rhizomes.

Leaves - Alternate, sessile, linear, 3-5 nerved, entire, slightly scabrous, acute to acuminate, to +/-10cm long, 8-9mm broad, reduced upward by inflorescence, glandular-punctate (use a lens to see).

Euthamia graminifolia leaves

Inflorescence - Corymbose arrangement of flower heads. Peduncles winged and pubescent to strigose on wing margins.

Euthamia graminifolia inflorescence

Involucre - 5mm tall, 2mm in diameter, cylindrical. Phyllaries imbricate, glabrous, yellowish and often with green apices (viewed with a lens you can see a yellow midvein in the green tip), linear, with scarious margins. Innermost phyllaries to 3.1mm long, .6mm broad.

Euthamia graminifolia involucreInvolucre.

Ray flowers - Fertile. Ligule yellow, to -3mm long, .5mm broad, glabrous. Achene (in flower) white, .5mm long, pubescent. Pappus of capillary bristles.

Disk flowers - 15-20 per flowerhead. Corolla tube to 2mm long, pale yellow, 5-lobed. Lobes yellow, 1.3mm long, acute, glabrous. Stamens 5, adnate 1/2 way up corolla tube. Anthers yellow, connate around style, included, 1.4mm long. Style bifurcate, just exserted beyond corolla lobes. Achene pubescent, .7mm long (in flower). Pappus of capillary bristles to 3.4mm long.

Flowering - August - October.

Habitat - Prairies, fields, railroads.

Origin - Native to U.S.

Other info. - graminifolia means "grass-leaf" and indeed the leaves on this species are thin and long, much like grass blades. This species is most common in the northeastern 1/4 of Missouri but is scattered in counties through the upper 1/2 of the state.
Steyermark gives two varieties for the plant. Variety media (Greene) Harris, is pictured and described above. Variety nuttallii (Greene) Fern., has leaves which are typically pubescent and more broad than the previous variety.

Photographs taken at Geneva State Park, Geneva, OH., 8-7-00.