Ambrosia trifida L.
  • Sp. Pl.: 987 (1753)

Cite taxon page as 'WFO (2021): Ambrosia trifida L. Published on the Internet; Accessed on: 04 Dec 2021'

General Information

Annuals, 30-150 cm. Stems erect. Leaves mostly opposite; petiole 10-30(-70) mm; blade orbicular-deltate to ovate or elliptic, 4-15(-25) × 3-7(-20) cm, usually some palmately 3(-5)-lobed, both surfaces scaberulose and gland-dotted, base truncate to cuneate, sometimes decurrent onto petiole, margin usually toothed, rarely entire. Female capitula clustered, proximal to male; floret 1. Male capitula: peduncles 1-3 mm; involucres saucer-shaped, 2-4 mm in diam., scaberulose; florets 3-25. Bur pyramidal, 3-5(-7) mm, glabrous or glabrate, spines 4 or 5, apical, acerose, 0.5-1 mm, tips straight. Fl. Jul-Aug, fr. Sep-Nov. 2n = 24, 48.

  • Provided by: [C].Flora Of CHina @
    • Source: [
    • 1
    • ]. 

    Annuals, 30–150(–400+) cm. Stems erect. Leaves mostly opposite; petioles 10–30(–70+) mm; blades rounded-deltate to ovate or elliptic, 40–150(–250+) × 30–70(–200+) mm, usually some blades palmately 3(–5)-lobed, bases truncate to cuneate (sometimes decurrent onto petioles), margins usually toothed, rarely entire, abaxial and adaxial faces ± scabrellous and gland-dotted. Pistillate heads clustered, proximal to staminates; florets 1. Staminate heads: peduncles 1–3+ mm; involucres ± saucer-shaped, 2–4 mm diam., scabrellous (often with 1–3 black nerves); florets 3–25+. Burs: bodies ± pyramidal, 3–5(–7+) mm, glabrous or glabrate, spines 4–5, ± distal, ± acerose, 0.5–1 mm, tips straight (bases ± decurrent as ribs). 2n = 24, 48.

  • Provided by: [D].Flora of North America @
    • Source: [
    • 2
    • ]. 

    "Coarse annual weed to 2(–5) m; stem spreading-hairy above, often glabrous below; lvs opposite, petiolate, ± scabrous, broadly elliptic to more often ovate or suborbicular, often 2 dm, serrate, palmately 3–5-lobed, or, especially in depauperate individuals, lobeless; staminate invols ca 1.5 mm, slightly oblique, unilaterally evidently 3-nerved; fruiting invols 5–10 mm, several- ribbed, each rib ending in a tubercle or spine; 2n=24. Moist soil and waste places throughout our range, s. to Fla., w. to B.C. and n. Mex. (July) Aug.–Oct. The common form in most of our range is var. trifida, with the petioles of at least the upper lvs ± wing-margined, and the ribs of the fr ending in short spines. (A. striata) From s. Ill. and Mo. to Miss., Ariz., and n. Mex. is found var. texana Scheele, with wingless petioles, and with the ribs of the mostly smaller fr ending in blunt or almost obsolete tubercles. (A. aptera)"

  • Provided by: [B].New York Botanical Garden
    • Source: [
    • 3
    • ]. 

     Information From

    CC0 1.0 Universal (CC0 1.0).
    • A CC0 1.0 Universal (CC0 1.0).
    New York Botanical Garden
    Descriptions of plants should be attributed to the full citation for each individual article, chapter or book that is the source for each record, which should include the authors of original publication.
    • B Content licensed under Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License
    Flora Of CHina @
    'Flora of China @ eFloras (2008). Published on the Internet [accessed August 2016]' Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
    • C Missouri Botanical Garden
    Flora of North America @
    'Flora of North America @ eFloras (2008). Published on the Internet [accessed August 2016]' Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
    • D Flora of North America Association
    World Flora Online consortium
    World Flora Online Data. 2018.
    • E CC0 1.0 Universal (CC0 1.0).