Annual Buckwheat - Eriogonum annuum
(see State Rank Reason below)
MNPS Threat Rank
State Rank Reason (see State Rank above)
Populations are common and widespread in most of eastern Montana, though population size will fluctuate due to its annual life-cycle.
- Details on Status Ranking and Review
ScoreDE - 1000 - 10,000 individuals
ScoreF - 20,000-200,000 sq km (~8,000-80,000 sq mi)
Area of Occupancy
ScoreE - 26-125 4-km2 grid cells
Number of Populations
ScoreC - 21 - 80
Number of Occurrences or Percent Area with Good Viability / Ecological Integrity
ScoreC - Few (4-12) occurrences with excellent or good viability or ecological integrity
ScoreC - Moderate. Generalist or community with some key requirements scarce
ScoreU - Unknown
ScoreU - Unknown
ScoreD - Low
CommentThreat categories include: Recreational activities.
ScoreU - Unknown
Plants: Gray-tomentose, taprooted annuals, biennials (Lesica 2012). Stems 1 to several, erect (Hitchcock et al. 1964), 20–60 cm tall (Lesica 2012).
Leaves: Basal leaves few and withering or falling by anthesis; stem leaves numerous, ascending, overlapping (often strongly so), becoming gradually smaller above (Hitchcock et al. 1964), 1-5 cm in length, oblanceolate (Lesica 2012), mostly alternate with entire margins (McGregor et al. 1986).
Inflorescence: An open cyme (Lesica 2012), branches splitting into two or three parts, the ends slightly spiraled (Hitchcock et al. 1964); bracts triangular; involucres 2–4 mm long with 5 to 6 erect lobes (Lesica 2012) barely 0.5 mm in length, with thick peduncles 1-3 (seldom 5) mm in length or sessile (Hitchcock et al. 1964). (P. Lesica's contribution adapted from Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX.)
Flowering July-September (McGregor et al. 1986).
Eastward of and including the foothills of the Rocky Mountains, MT, ND south to NM, TX, and into Mexico (Hitchcock et al. 1964; Lesica 2012).
(P. Lesica's contribution adapted from Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX.)
Observations in Montana Natural Heritage Program Database
Number of Observations:
(Click on the following maps and charts to see full sized version)
Map Help and Descriptions
(Observations spanning multiple months or years are excluded from time charts)
The dense woolly leaves aid the plant in surviving dry periods (Haddock 2007) by protecting the foliage from air movement and thus slowing transpiration.
Flowers: Flowers unisexual (Hitchcock et al. 1964); perianth 1–3 mm long, white to pink, cup-shaped (Lesica 2012), with a connate base, smooth on the outside and woolly on the inside, the outer tepals much wider than the inner (Hitchcock et al. 1964); stamens included (Lesica 2012); ovary smooth (Hitchcock et al. 1964).
Fruit: Achenes 1–2 mm long (Lesica 2012). (P. Lesica's contribution adapted from Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX.)
This species flowers only once before dying (monocarpic). Although often considered an annual, it is likely biennial (Thieret 1964) more often than annual, and possibly a perennial on occasion (Hitchcock et al. 1964).
Pérez et al. (1998) found germination of E. annuum seeds to be low (2% or less) from a seedbank holding high numbers of E. annuum seeds.
It is sometimes considered weedy in the Great Plains (Denver Botanic Gardens) and serves as an indicator of overgrazing (Clements 1920) and disturbance. For example, Hunt and Best (2010) found E. annuum growing more commonly on the highly disturbed soils of abandoned Lesser Prairie-Chicken (Tympanuchus pallidicinctus) leks than on active leks.
- Literature Cited AboveLegend: View Online Publication
- Clements, F.E. 1920. Plant indicators: the relation of plant communities to process and practice. Washington, D.C.: Carnegie Institution of Washington. 388 p.
- Denver Botanic Gardens: outreach, collaboration and education about the Gardens and their conservation programs. Annual Eriogonum; Annual Buckwheat.
- Haddock, Mike. October 26, 2007. Kansas Wildflowers & Grasses: information and photos for 849 plant species growing in Kansas. Annual Eriogonum.
- Hitchcock, C. L., A. Cronquist, M. Ownbey, and J. W. Thompson. 1964. Vascular Plants of the Pacific Northwest. Part 2: Salicaceae to Saxifragaceae. University of Washington Press, Seattle. 597 pp.
- Hunt, J.L. and T.L. Best. 2010. Vegetative characteristics of active and abandoned leks of Lesser Prairie-Chickens (Tympanuchus pallidicinctus) in Southeastern New Mexico. The Southwestern Naturalist 55(4):477-487.
- Lesica, P., M. T. Lavin, and P. F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.
- McGregor, R.L., coordinator, and T.M. Barkley, R.E. Brooks, and E.K. Schofield, eds.: Great Plains Flora Association. 1986. Flora of the Great Plains. Lawrence, KS: Univ. Press Kansas. 1392 pp.
- Moerman, D.E. 1998. Native American ethnobotany. Portland, OR: Timber Press, Inc. 927 p.
- Pérez, C.J.; S.S. Waller, L.E. Moser, J.L Stubbendieck, and A.A. Steuter. 1998. Seedbank characteristics of a Nebraska Sandhills Prairie. Journal of Range Management 51(1):55-62.
- Thieret, J.W. 1964. Eriogonum annuum (Pologonaceae) biennial in Nebraska. SIDA, Contributions to Botany 1(6):382.
- Additional ReferencesLegend: View Online Publication
Do you know of a citation we're missing?
- Britton, N. L. and A. B. Brown. 1913. An Illustrated Flora of the Northern United States, Canada, and the British Possessions. 2nd Edition in 3 Volumes. New York, NY: Charles Scribner's Sons. B13BRI01PAUS.