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Montana Field Guide

Montana Field Guides

Redroot Amaranth - Amaranthus retroflexus


Global Rank: G5
State Rank: SNA
* (see State Rank Reason below)

Agency Status
USFWS:
USFS:
BLM:
MNPS Threat Rank:
C-value: 2

External Links






State Rank Reason (see State Rank above)
Native to parts of eastern and central North America and introduced into Montana. This is the most abundant pigweed in the state.
 
General Description
Monoecious. Stems erect, reddish below, 10–100 cm with sparsely pubescent foliage. Leaf blade lanceolate to ovate, 2–10 cm long, just longer than petiole. Inflorescence often red-tinged, dense, terminal and axillary panicles; bracts lanceolate-attenuate, 3–5 mm long, short-pointed. Flowers: sepals 5, ca. 3 mm long with blunt to rounded tips and excurrent midveins; stamens 4 to 5. Utricle ca. 2 mm, nearly as long as sepals (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Species Range
Unknown/Undetermined
 


Range Comments
Known from nearly every MT county; throughout N. America (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Summary of Observations Submitted for Montana
Number of Observations: 5

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

Recency

 

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



Habitat
Cultivated fields, roadsides, stream banks; plains, valleys (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

References
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Citation for data on this website:
Redroot Amaranth — Amaranthus retroflexus.  Montana Field Guide.  .  Retrieved on , from