White Amaranth - Amaranthus albus
State Rank Reason (see State Rank above)
Amaranthus albus is a cosmopolitan species whose origin is unknown. It is likely native to North America but its distribution is weedy, its annual life cycle can make populations short-lived, herbarium specimens are sometimes mis-identified, and other factors can make it difficult to accurately assess its distribution. In Montana it occupies disturbed pastures, roadsides, cultivated fields, and streambanks, and may have been introduced from the central United States. However, some botanists believe it should be considered “likely native” in Montana and further examination of Montana specimens and historical accounts are needed.
A conservation status rank is not applicable (SNA) because the plant in Montana is not a suitable target for conservation activities.
Monoecious. Stems erect, 10–75 cm with glabrous to pubescent foliage, branched at the base, becoming a tumbleweed. Leaf blade 1–3 cm long, longer than the petiole, obovate with a minute spine tip. Inflorescences axillary glomerules; bracts lanceolate and long attenuate, spine-tipped, 2–3 mm long. Flowers: sepals 3, narrowly lanceolate, acute, 1–2 mm long; stamens 3. Utricle 1–2 mm, as long or longer than sepals; seed <1 mm long (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX)
Scattered across much of MT; throughout North America (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).
Observations in Montana Natural Heritage Program Database
Number of Observations:
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(Observations spanning multiple months or years are excluded from time charts)
Cultivated fields, disturbed pastures, roadsides, streambanks; plains, valleys (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX)
- Additional ReferencesLegend: View Online Publication
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- Jones, W. W. 1901. Preliminary flora of Gallatin County. M.S. Thesis. Bozeman, MT: Montana State College. 78 pp.
- Lesica, P., M.T. Lavin, and P.F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.
- Seipel, T.F. 2006. Plant species diversity in the sagebrush steppe of Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 87 p.
- Sirirugsa, P. 1973. Descriptive analysis of Montana species of Amaranthus. M.Sc. Thesis. Bozeman, MT: Montana State University. 56 p.