Ambrosia tomentosa Nutt.

Cite taxon page as 'WFO (2021): Ambrosia tomentosa Nutt. Published on the Internet; Accessed on: 27 Oct 2021'

General Information

Perennials, 10–30+ cm. Stems erect. Leaves mostly alternate; petioles 8–25(–35+) mm; blades elliptic to lance-elliptic, 50–80(–180+) × 12–20(–50+) mm overall, (1–)2(–3)-pinnately lobed (lobes ± deltate), bases cuneate, ultimate margins with ± deltate teeth, abaxial faces densely finely scabrellous (silvery gray), adaxial faces strigillose. Pistillate heads clustered, proximal to staminates; florets (1–)2. Staminate heads: peduncles 2–9 mm; involucres saucer-shaped (with black nerves), 3–6+ mm diam., strigillose; florets 25–40+. Burs: bodies ± pyriform, somewhat flattened, 1.5–2.5(–4) mm, finely scabrellous, spines (1–)8–12+, scattered, stoutly conic, 0.5–1+ mm, tips straight.

  • Provided by: [C].Flora of North America @
    • Source: [
    • 1
    • ]. 

    "Colonial perennial from creeping roots; lvs all or nearly all alternate, densely and conspicuously short-white-hairy beneath, greener and less hairy above, openly subbipinnatifid to subtripinnatifid with short and broad ultimate segments, the slender midstrip beset with small segments between the major ones; fruiting invols 4–6 mm, 2-seeded, with 2 sharp beaks and to 10 short spines in one or more cycles. Plains sp., casually intr. as far e. as Wis. and Ill. May–Aug. (Franseria discolor; Gaertneria d. not Franseria tomentosa, properly A. grayi (A. Nelson) Shinners, another Great Plains sp., with less dissected lvs that have a large terminal segment)"

  • Provided by: [B].New York Botanical Garden
    • Source: [
    • 2
    • ]. 


     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 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.
    • C Flora of North America Association
    World Flora Online consortium
    World Flora Online Data. 2018.
    • D CC0 1.0 Universal (CC0 1.0).