Helianthus Linnaeus (Q2749)

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Helianthus is a taxon with the rank genus within the tribe Heliantheae
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English
Helianthus Linnaeus
Helianthus is a taxon with the rank genus within the tribe Heliantheae

    Statements

    taxon/id/Helianthus Linnaeus
    0 references
    Helianthus Linnaeus
    Helianthus
    Linnaeus
    FNA Editorial Committee. 2006. Flora of North America north of Mexico. Volume 21: Magnoliophyta: Asteridae, part 8: Asteraceae, part 3. Oxford University Press, New York.
    accepted
    Sunflower (English)
    tournesol (English)
    North America
    Mexico
    in the Old World
    Stems erect or ascending to decumbent or procumbent, usually branched distally.
    petiolate or sessile;
    blades usually 3-nerved (1-nerved in H. eggertii, H. smithii, and H. maximiliani), mostly deltate, lance-linear, lanceolate, lanceovate, linear, or ovate, bases cordate to narrowly cuneate, margins usually entire or serrate, rarely lobed, faces glabrous or hairy, often glanddotted.
    Heads usually radiate (sometimes discoid in H. radula), borne singly or in ± corymbiform, paniculiform, or spiciform arrays.
    Involucres usually ± hemispheric, sometimes campanulate or cylindric, 5–40+ (–200+ in cultivars) mm diam.
    Phyllaries persistent, 11–40 (–100+ in cultivars) in 2–3+ series (subequal to unequal).
    Receptacles flat to slightly convex (conic in H. porteri), paleate (paleae ± conduplicate, usually rectangular-oblong, usually ± 3-toothed, sometimes entire, apices sometimes reddish or purplish).
    Ray-florets usually 5–30+ (–100+ in cultivars), rarely 0, neuter;
    corollas usually yellow.
    Disc-florets (15–) 30–150+ (–1000+ in cultivars), bisexual, fertile;
    corollas yellow or reddish (at least distally), tubes shorter than campanulate throats, lobes 5, triangular (style-branches slender, appendages ± attenuate).
    Cypselae (usually purplish black, sometimes mottled) ± obpyramidal, ± compressed (glabrous, glabrate, or ± hairy);
    pappi 0 (H. porteri), or readily falling, of 2 (–3) usually lanceolate, aristate, or erose scales (at the 2 principal angles, 1–5 mm) plus 0–8 usually shorter scales (0.2–2 mm).