Helenium flexuosum Raf.
Family - Asteraceae
Stems - To 1m tall, erect,
typically single from base, from fibrous roots, branching above, herbaceous,
heavily winged from decurrent leaf tissue, scabrous, strigose. Wings of
stem to 5mm broad.
Leaves - Basal leaves lanceolate
to elliptic, to +20cm long, scabrous, strigose, entire to lobed. Cauline
leaves alternate, lanceolate, acute, entire or with few shallow teeth,
scabrous, densely strigose, to +10cm long, -2cm broad, reduced above, with
heavily decurrent tissue from base.
Inflorescence - Flower heads in loose corymbiform cluster at apex of stems. Peduncles carinate, densely strigose, scabrous.
Involucre - Phyllaries linear,
attenuate, reflexed at maturity and curling, in one series, 1-1.4cm long,
2.1mm broad, strigose abaxially and on margins, glabrous adaxially.
Involucre.
Ray flowers - Ligules yellow,
to 2.5cm long, -2cm broad, 5-lobed at apex, tapering to base, densely pubescent
below, glabrous above. Flowers sterile. Achenes flattened, short pubescent.
Pappus of awn- tipped scales.
Disk flowers - Disk to 1.5cm
broad and tall, domed to globose. Receptacle ovoid. Corolla tube of disk
flowers yellow, 2-3mm long, 4-lobed, dark maroon at apex because of dense
glandular pubescence. Styles bifurcate, yellow. Flowers fertile. Achenes
pubescent, 1.2mm long in flower. Pappus of 5-6 awn-tipped scales.
Flowering - June - November.
Habitat - Pond margins, streambanks, ditches, swamps, wet meadows, wet depressions of prairies, pastures, moist areas of glades.
Origin - Native to U.S.
Other info. - H.
flexuosum and other species in the genus contain a lactone
known as Helenalin. This compound is poisonous to various animals but has
anti-cancer properties. This species is often found standing alone in pastures
as cows will not eat it. The plant is quite striking when in full flower
and I think it should be cultivated more. It's a great plant to grow in
those difficult wet areas of a yard.
H. felxuosum is easy to ID in the field because of the heavily winged stems and brown disk flowers.
Photographs taken at Bethel Prairie, Barton County, MO., 7-4-03.
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