BioGator | University of Florida - Ambrosia artemisiifolia

Ambrosia artemisiifolia L.
Family: Asteraceae Annual Ragweed, more...common ragweed Chase G. Mayers	FNA Gleason & Cronquist Resources John L. Strother in Flora of North America (vol. 21) Annuals, 10-60(-150+) cm. Stems erect. Leaves opposite (proximal) and alternate; petioles 25-35(-60+) mm; blades deltate to lanceolate or elliptic, 25-55(-90+) × 20-30(-50+) mm, 1-2-pinnately lobed, bases cuneate, ultimate margins entire or toothed, abaxial faces sparsely pilosulous to strigillose, adaxial faces strigillose, both gland-dotted. Pistillate heads clustered, proximal to staminates; florets 1. Staminate heads: peduncles 0.5-1.5 mm; involucres shallowly cup-shaped (usually without black nerves), 2-3+ mm diam., glabrous or hispid to pilosulous; florets 12-20+. Burs: bodies ± globose to pyriform, 2-3 mm, ± pilosulous, spines or tubercles 3-5+, near middles or distal, ± conic to acerose, 0.1-0.5+ mm, tips straight. 2n = 34, 36. Flowering Jul-Oct. Wet to dry soils, disturbed sites; 0-1000+ m; Alta., B.C., Man., N.B., Nfld. and Labr. (Nfld.), N.W.T., N.S., Ont., P.E.I., Que., Sask.; Ala., Alaska, Ariz., Ark., Calif., Colo., Conn., Del., D.C., Fla., Ga., Idaho, Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., Mont., Nebr., Nev., N.H., N.J., N.Mex., N.Y., N.C., N.Dak., Ohio, Okla., Oreg., Pa., R.I., S.C., S.Dak., Tenn., Tex., Utah, Vt., Va., Wash., W.Va., Wis., Wyo. Hybrids between Ambrosia artemisiifolia and A. psilostachya have been called A. ×intergradiens W. H. Wagner. The name Ambrosia ×helenae Rouleau applies to hybrids between A. artemisiifolia and A. trifida. Vascular plants of NE US and adjacent Canada Annual weed 3-10 dm, branching at least above, variously hairy or in part subglabrous; lvs opposite below, alternate above, once or more often twice pinnatifid, the blade narrowly to broadly ovate or elliptic in outline, 4-10 cm, the middle and lower ones, at least, evidently petiolate; staminate invols short-pedunculate, symmetrical or slightly oblique, inconspicuously nerved; fruiting invols 3-5 mm, 1-fld and 1 beaked, with a single series of short, sharp, erect spines near or above the middle; 2n=34, 36. Waste places; throughout our range, w. to the Pacific. (July) Aug.-Oct. (A. elatior; A. media) Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp. ©The New York Botanical Garden. All rights reserved. Used by permission.
Open Interactive Map Everglades Holiday Park sandrae34242 ashleyraejordan Tom Joe MDO Steven Rowe amandatheaquarist JeffreyGammon Mike Ostrowski Jessica Bickell eleacoop Tom Palmer luu_j_21 esthor Joe MDO arenap Joe MDO Emily Le Falchier kimberlycleveland Susan J. Hewitt Scott C nat_t Tom sandrae34242 jfigu099 focus jade fortnash melanycutie foliver_2018 Damon Tighe xva carissagreeneyes JC Joe MDO Joseph Cripe Erik obrock Joshua Doby doiron_k_004 marcie_praetorius Susan J. Hewitt Andy Newman Sylvain Piry Alex Abair sandy bauerschmidt Sean Patton Joe MDO Claire Gentry ashley0699 jade fortnash Val iammermaid Nick Moore Lindsay Alex Abair Matt Parr bronzit kyva Ashley M Bradford Joe MDO earthjenna Josiah Londeree beejax moth_moe Stephanie Robinson Tom Palmer jade fortnash Joe MDO leilaalsahli James Wetterer sonia_stephens jstevenson67 Eridan Xharahi Whalen Dillon Ben Machado itskaibrown Scott Allen Davis Joe MDO kerrypad jimbo51 Lauren Whitehurst sandrae34242 marsbats Josiah Londeree Ingolf Askevold Eric Blomberg mrsmithicals tonkabean Leann Hill Liz Childress sandrae34242 alstanford Joseph Cripe jcusfgcu sunnybean1244 Javier Alejandro isabelnewman nikkie_b9 Kaylynn Low Click to Display 100 Initial Images - - - - - View All Images