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Annual sumpweed

Also known as: Annual marshelder

Iva annua L.

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Annual sumpweed
Annual sumpweed
Annual sumpweed leaf
Annual sumpweed
Annual sumpweed
Annual sumpweed
Annual sumpweed inflorescence
Annual sumpweed
Annual sumpweed
Annual sumpweed

Morphology

Stem
Usually erect, usually branched.
Leaves
Cauline, mostly opposite, distal sometimes alternate; petiole .2 to 1.2 inch; blade deltate to ovate, lanceolate, or elliptic, 1.2 to 6 inches long, .4 to 3.2 inches wide, base acute to acuminate or truncate, margins coarsely serrate, surfaces rough.
Inflorescence
Heads discoid, sessile in spike-like arrays, solitary in axils of linear to ovate bracts, containing both pistillate and staminate florets, pistillate florets peripheral, staminate central; peduncles short; involucral 1/6 to 1/5 inch across, involucral bracts 3-5, subtending the mature achenes.
Flower
Pistillate florets 3-5; corolla white, tubular, 1/50 to 1/25 inch. Staminate florets 8-12; corolla white, funnelform, 1/12 to 1/10 inch, lobes 5.
Fruit
Achenes brown to brownish black, obovoid to pyriform, 1/12 to 1/6 inch, pappus absent.

Ecology

Habitat
Moist ground in disturbed sites
Distribution
East 6/7 of Kansas
Quick Facts
Plant Type
Wildflower
Family
Asteraceae - Sunflower Family
Life Span
Annual
Height
8-48 inches
Origin
Native
Last Updated
2014-05-24
Color Groups
White, Green & Greenish White Wildflowers
Flowering Period
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Blooms: August, September, October