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Montana Field Guide

Montana Field Guides

Smooth Amaranth - Amaranthus hybridus
Other Names:  Slim Amaranth

Non-native Species

Global Rank: G5?
State Rank: SNA
(see State Rank Reason below)
C-value: 1

Agency Status


External Links

State Rank Reason (see State Rank above)
Native to parts of the western hemisphere, likely introduced into Montana. Seldom collected in the state.
General Description
Monoecious. Stems erect, 30–100 cm with glabrous or sparsely hairy foliage. Leaf blade lanceolate to ovate, 1–8 cm long, longer than petiole. Inflorescence green, dense, cylindric spikes in terminal and sometimes axillary panicles; bracts lanceolate, spine-tipped, 3–4 mm long. Flowers: sepals 5, lanceolate, 1.5–2 mm long with excurrent midveins; stamens 4 to 5. Utricle 1.5–2 mm long, shorter than sepals (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Species Range
Montana Range Range Descriptions


Range Comments
In MT in some of the western counties; native to S. America but introduced throughout North America (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Observations in Montana Natural Heritage Program Database
Number of Observations: 11

(Click on the following maps and charts to see full sized version) Map Help and Descriptions
Relative Density



(Observations spanning multiple months or years are excluded from time charts)



  • Literature Cited AboveLegend:   View Online Publication
    • Lesica, P., M.T. Lavin, and P.F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.
  • Additional ReferencesLegend:   View Online Publication
    Do you know of a citation we're missing?
    • Sirirugsa, P. 1973. Descriptive analysis of Montana species of Amaranthus. M.Sc. Thesis. Bozeman, MT: Montana State University. 56 p.
  • Web Search Engines for Articles on "Smooth Amaranth"
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Citation for data on this website:
Smooth Amaranth — Amaranthus hybridus.  Montana Field Guide.  .  Retrieved on , from