: Toxic to mammals and insects due to the presence of lactone tenulin.
: Perennial herb from a fibrous root; stems erect, solitary or few; sometimes branched at the base, branched above, minutely hairy with upwardly-curved hairs or nearly glabrous, 0.15-1.2 m tall.
: Basal leaves soon deciduous, stem leaves alternate, numerous, glandular-dotted, usually wing-margined at the base, lanceolate, narrowing to an unstalked or almost unstalked base, shallowly toothed or nearly entire, 3-15 cm long, 5-40 mm wide.
: Heads with ray and disk flowers, several to numerous, terminal, involucres are 6-8 mm tall, involucre bracts are narrow, 10-20 ray flowers, yellow in color, 3-lobed, 1-2.5 cm long.
Fruit and seeds
: Achenes angled, appressed stiff-hairy on the angles, pappus of egg-shaped or lanceolate, long-pointed scales; broadened at the base, about 1/2 the length of the disk flowers.
: Found in stream banks and other moist, low ground in the valleys and foothills.
: By seed.
: Purple-head sneezeweed (Helenium flexuosum
) and Common sneezeweed (Helenium autumnale
Monitoring and rapid response
: Effectively controlled by any of the several readily available general use herbicides before the plant flowers.
: The information provided in this factsheet was gathered from the Lady Bird Johnson Wildflower Center, the USDA PLANTS Database and the University of British Columbia.
Individual species images that appear with a number in a black box are courtesy of the Bugwood.org network (http://www.invasive.org).Individual photo author credits may not be included due to the small display size of the images and subsequent difficulty of reading the provided text. All other images appear courtesy of Google (http://images.google.com).