Taenidia integerrima (L.) Drude

Yellow Pimpernel

Taenidia integerrima plant

Family - Apiaceae

Stems - To +/-1m tall, glabrous, often glaucous, erect, herbaceous, fistulose, fragrant, branching near the apex, from a taproot.

Leaves - Alternate, petiolate below, sessile above, 2-3 ternately compound, glabrous. Petioles expanded and sheathing at the base, to 13cm long. Leaflets entire, oblong to elliptic or oblanceolate, mucronate (commonly), +/-2.5cm long, +/-1cm broad, glaucous abaxially.

Taenidia integerrima leaf

Inflorescence - Terminal and lateral compound umbels with +/-10 rays per umbel. Peduncles glabrous, to +/-10cm in fruit. Rays glabrous, -4cm long. Raylets 2-5mm long. No bracts subtending any of the rays.

Flowers - Petals 5, yellow, spreading or (more commonly) inflexed, apiculate, to 2mm long. Stamens 5, exserted, erect to spreading. Filaments pale yellow, glabrous, to 2.5mm long. Anthers pale yellow, .5-.6mm long. Styles 2, +2mm long, spreading and twisted, glabrous, whitish at the base, purplish near the apex. Stylopodium green, thick. Ovary inferior, slightly compressed, glabrous, 2-locular. One seed per locule. Flowers have a tendency to be either pistillate (with reduced to no stamens) or staminate (with reduced pistil).

Taenidia integerrima flowers

Flowering - May - July.

Habitat - Rocky and dry open woods or upland woods, prairies, ledges along bluffs.

Origin - Native to U.S.

Other info. - This species can be found through Missouri but is most common in the Ozarks. The plant is easy to ID either in flower or vegetatively because of its big leaves, which have oblong and entire leaflets. In flower, of course, the yellow flowers are a good characteristic for ID as no other member of our flora has the plants distinct combination of yellow flowers and oblong leaflets.

Photographs taken at the Buffalo Creek Recreational Area, Ripley County, MO., 5-20-01.