- Ascending to erect, to 80 cm, branching, 4-angled (the angles rounded), fluted, essentially glabrous but sometimes with sparsely hairy nodes in upper portions, typically purple.
- Opposite, petiolate, mostly compound. Petiole to 5 cm long, with an adaxial groove (groove curly pubescent within), the rest of the petiole glabrous or with very sparse short pubescence. Lateral leaflets on stalks to 5-6 mm long, basally oblique. Terminal leaflets on stalks to 2.5 cm long, larger than lateral leaflets, sometimes unequally divided. All leaflets sharply toothed, lanceolate, acuminate, usually glabrous above and pubescent below, to 10 cm long, 4 cm broad, light green below, deep dull green above.
- Solitary terminal heads or loose clusters of heads.
- Involucre with the outer series of 5-8 bracts 5-25 mm long, ascending to spreading, leaflike, linear to narrowly oblanceolate, the margins entire but with short, spreading hairs, at least toward the base, the outer surface glabrous or sparsely and minutely hairy, especially toward the base; the inner series of 6-12 bracts 5-9 mm long, oblong to narrowly ovate or ovate, glabrous. Chaffy bracts thin and translucent, narrowly oblong to oblong-lanceolate, with narrow to broad, yellowish margins but sometimes purplish-tinged at the tip, glabrous.
- Usually absent.
- 20-100 per head, the corollas 2.5-4.0 mm long, 5-lobed, yellow, glabrous. Pappus of 2 awns 2-7 mm long, these with downward-pointed barbs (upward-pointed elsewhere), erect to somewhat spreading at fruiting. Stamens 5, fused at apex of contracted portion of corolla tube. Filaments glabrous, whitish, 1.3 mm long. Anthers partially exserted, 1 mm long, purplish. Style exserted, bifurcate, yellowish at apex (stigmas).
- Achenes 5-12 mm long, with 2 retrorsely-barbed awns, wedge-shaped to oblong-obovate, often slightly 3- or 4-angled (1 or both faces sometimes with a broad, low longitudinal angle or ridge), the angles with minute, stiff, usually ascending hairs, the faces dark brown to black, moderately to densely pubescent with fine, more or less appressed hairs.
appear similar, having flowering heads which lack rays florets. Differentiation from
in particular can be difficult.
- This species of
occurs throughout Missouri, and also throughout much of the U.S. and into Canada. It is common in wet places but is inconspicuous, with the flowering heads usually lacking ray florets. Even when present, these are small and few in number. Differentiation of this plant from the very similar
hinges on the number of spreading involucral bracts.
should have 5-8 of these, whereas
has a larger number (10-21). The plant described above has been called
which has the retrorse barbs on its awns. Form
(Porter) Fern. has barbs which are antrorse on the awns. This latter form has not been found in Missouri.
Because this species grows close to water, it is eaten by muskrats. The achenes are eaten by ducks. Late in the season, the achenes announce their presence to humans by embedding large numbers of themselves into socks and clothing.
Photographs taken at The Summit Conference Center, Brown Summit, NC., 9-14-01, and along the shores of the Current River, Shannon County, MO., 9-20-03 (DETenaglia); also at Cuivre River State Park, Lincoln County, MO, 8-25-2008, and Salt Lick Point, Monroe County, IL, 9-26-2011 (SRTurner).
Robert H. Mohlenbrock. USDA SCS. 1989.
Midwest wetland flora: Field office illustrated guide to plant species
. Midwest National Technical Center, Lincoln. Provided by USDA NRCS Wetland Science Institute (WSI).
This plant can be weedy or invasive according to the authoritative sources noted below.This plant may be known by one or more common names in different places, and some are listed above. Click on an acronym to view each weed list, or click here for a composite list of
Weeds of the U.S.
Linnaeus, Sp. Pl. 2: 832. 1753.
Porter ex Fernald;
Fernald & H. St. John;
petioles 10—40(—60) mm; blades deltate to lance-ovate overall, 30—80(—150+) × 20—60(—100+) mm, 3(—5)-foliolate, leaflets petiolulate, lanceolate to lance-ovate, (15—)35—60(—120) × (5—)10—20(—30) mm, bases cuneate, margins dentate to serrate, sometimes ciliate, apices acuminate to attenuate, faces glabrous or hirtellous.
usually borne singly, sometimes in 2s or 3s or in open, corymbiform arrays.
of (5—)8(—10) ascending to spreading, spatulate or oblanceolate to linear, sometimes ± foliaceous bractlets or bracts 5—20(—60) mm, margins usually ciliate, abaxial faces glabrous or hirtellous.
campanulate to hemispheric or broader, 6—9 × 7—12 mm.
6—12, oblong or ovate to lance-ovate, 5—9 mm.
0 or 1—3+; laminae golden yellow, 2—3.5 mm.
20—60(—120+); corollas ± orange, 2.5—3+ mm.
blackish to brown or stramineous, ± obcompressed, obovate to cuneate, outer 5—7 mm, inner 7—10 mm, margins antrorsely or retrorsely barbed, apices ± truncate to concave, faces usually 1-nerved, sometimes tuberculate, glabrous or sparsely hirtellous;
of 2 ± erect to spreading, antrorsely or retrorsely barbed awns 2—5 mm.
= 24, 48, 72.
Infusions and tinctures of
are rated as outstanding herbal therapies for irritation, inflammation, pain, and bleeding of the urinary tract mucosa and are used for benign prostatic hypertrophy and increasing excretion of uric acid, decreasing the risk of gout attacks, as well as other medical uses (M. Moore 1993).
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