Xanthium Linnaeus (Q2807)

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Xanthium is a taxon with the rank genus within the tribe Heliantheae
Language Label Description Also known as
English
Xanthium Linnaeus
Xanthium is a taxon with the rank genus within the tribe Heliantheae

    Statements

    taxon/id/Xanthium Linnaeus
    0 references
    Xanthium Linnaeus
    Xanthium
    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
    Lampourde (English)
    New World
    nearly worldwide
    Stems erect, branched.
    blades lanceolate, linear, ovate, rounded-deltate, or suborbiculate, often ± palmately or pinnately lobed, ultimate margins entire or ± toothed, faces hirtellous or ± strigose, usually glanddotted as well.
    Heads discoid, either pistillate (proximal) or functionally staminate (distal), in racemiform to spiciform arrays or borne singly (in axils).
    Pistillate heads: involucres ± ellipsoid, 2–5+ mm diam. at anthesis (6–20+ mm diam. at maturity);
    phyllaries 30–75+ in 6–12+ series, outer 5–8 distinct, the rest (sometimes interpreted as paleae) proximally connate, their distinct tips mostly ± hooked (the distal 1–3 usually longer, stouter, and not hooked), the whole becoming a hard, prickly perigynium (a bur);
    florets 2, corollas 0.
    Staminate heads: involucres ± saucer-shaped, 3–5 mm diam.;
    phyllaries 6–16+ in 1–2+ series, distinct to bases;
    receptacles conic to columnar;
    paleae spatulate to cuneiform or linear, membranous, distally ± villous or hirtellous;
    florets 20–50+, corollas whitish, ± funnelform, lobes 5, erect or reflexed (filaments connate, anthers distinct or weakly coherent).
    Cypselae (black) ± fusiform, enclosed in obovoid to ellipsoid, hard, prickly, 2-chambered burs;