Hybrid Prairie Sunflower - Helianthus x laetiflorus
(see State Rank Reason below)
MNPS Threat Rank
State Rank Reason (see State Rank above)
Hybrid between H. tuberosus and H. pauciflorus; reported for Montana.
Rhizomatous perennials. Stems 100-200 cm tall, erect, slightly hairy. Leaves basal and cauline; mostly opposite; petioles 1–5 cm; blades lanceolate to lance-ovate, 10–25 × 2–8 cm, bases cuneate, margins serrulate to serrate, abaxial faces sparsely hispid, gland-dotted. Heads 3–6. Peduncles 7–14 cm. Involucres hemispheric, 14–18 mm in diameter. Phyllaries 25–35, oblong-lanceolate, 7–12 × 3–3.5 mm (strongly unequal), apices acuminate, abaxial faces usually puberulent, gland-dotted. Paleae (sterile bracts on receptacle) 9–10 mm, entire or 3-toothed (apices reddish). Ray florets 15–20; laminae 25–37 mm. Disc florets 75+; corollas 7–7.5 mm, lobes reddish (at least at tips); anthers dark, appendages dark to yellowish (style branches yellow). Fruit(seldom formed) 4–5 mm, glabrate; pappus of 2 aristate scales 2.5–3.5 mm (adapted from: Schiller, 2006, Fl. North America, Vol. 21).
Flowering in late summer.
Mostly in eastern North America east of Latitude 100 (Kartesz 2009).
Observations in Montana Natural Heritage Program Database
Number of Observations:
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(Observations spanning multiple months or years are excluded from time charts)
Roadsides and fields.
The following animal species have been reported as pollinators of this species or genera where their geographic ranges overlap: Bombus vagans
, Bombus appositus
, Bombus centralis
, Bombus fervidus
, Bombus flavifrons
, Bombus huntii
, Bombus nevadensis
, Bombus rufocinctus
, Bombus pensylvanicus
, Bombus bimaculatus
, Bombus griseocollis
, Bombus impatiens
, Bombus insularis
, and Bombus flavidus
(Thorp et al. 1983, Mayer et al. 2000, Colla and Dumesh 2010, Colla et al. 2011, Koch et al. 2012, Williams et al. 2014).
- Literature Cited AboveLegend: View Online Publication
- Colla, S., L. Richardson, and P. Williams. 2011. Bumble bees of the eastern United States. Washington, DC: USDA Forest Service, Pollinator Partnership. 103 p.
- Colla, S.R. and S. Dumesh. 2010. The bumble bees of southern Ontario: notes on natural history and distribution. Journal of the Entomological Society of Ontario 141: 39-68.
- Koch, J., J. Strange, and P. Williams. 2012. Bumble bees of the western United States. Washington, DC: USDA Forest Service, Pollinator Partnership. 143 p.
- Mayer, D.F., E.R. Miliczky, B.F. Finnigan, and C.A. Johnson. 2000. The bee fauna (Hymenoptera: Apoidea) of southeastern Washington. Journal of the Entomological Society of British Columbia 97: 25-31.
- Thorp, R.W., D.S. Horning, and L.L. Dunning. 1983. Bumble bees and cuckoo bumble bees of California (Hymenoptera: Apidae). Bulletin of the California Insect Survey 23:1-79.
- Williams, P., R. Thorp, L. Richardson, and S. Colla. 2014. Bumble Bees of North America. Princeton, NJ. Princeton University Press.
- Additional ReferencesLegend: View Online Publication
Do you know of a citation we're missing?
- Lesica, P., M.T. Lavin, and P.F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.