Dipsacus sylvestris Huds. - Teasel
Family - Dipsacaceae
Stems - To +2m tall, from stout taproot, erect, herbaceous, carinate, with flattened straight prickles, branching above or simple.
Leaves - Opposite, linear-lanceolate, sessile, to +20cm long, +6cm broad, glabrous, with prickles on midrib (below) and on margins, acute. often basally connate. Basal leaves often drying by anthesis.
Inflorescence - Dense ovoid pedunculate cluster of many flowers terminating stem. Cluster subtended by ascending bracts to +/-10cm long. Bracts with straight prickles. Each flower subtended and cupped by an awn tipped chaff to +2cm long. Chaff pubescent, green to purple at apex.
Flowers - Corolla lavender at apex, whitish near base, to +1cm long, 4-lobed, dense pubescent on tube portion. Stamens 4, alternating with corolla lobes, adnate near apex of corolla tube, exserted. Filaments glabrous. Style well exserted, glabrous, white. Calyx tubular, 4-angled, 4-lobed, green. Achenes to +5mm long.
Flowering - June - October.
Habitat - Fields, thickets, pastures, waste ground, open woods, roadsides, railroads.
Origin - Native to Europe.
Other info. - This species
and the closely related D. laciniatus L. are noxious
weeds in Missouri and throughout their range in the U.S.. The fruiting
heads produce many small achenes and the plant is easily spread and hard
Photographs taken off Highway 77 near Partensburg, West Virginia, 7-20-02.