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.
- Additional ReferencesLegend: View Online Publication
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- Lesica, P., M. T. Lavin, and P. F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.