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Montana Field Guide

Montana Field Guides

Oniongrass - Melica bulbosa

Native Species

Global Rank: G5
State Rank: S4
(see State Rank Reason below)

Agency Status
MNPS Threat Rank:
C-value: 5

External Links

State Rank Reason (see State Rank above)
Melica bulbosa occurs scattered throughout central and western Montana.
  • Details on Status Ranking and Review
    Oniongrass (Melica bulbosa) Conservation Status Review
    Review Date = 08/26/2016
    View State Conservation Rank Criteria
    Population Size

    ScoreU - Unknown

    Range Extent

    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

    Environmental Specificity

    ScoreD - Broad. Generalist or community with all key requirements common

    Long-term Trend

    ScoreU - Unknown


    ScoreU - Unknown


    ScoreU - Unknown

    CommentThreats: Unknown/undetermined.

    Intrinsic Vulnerability

    ScoreC - Not intrinsically vulnerable

General Description
Plants: Bunchgrass. Stems 30–80 cm tall, often few-bunched, each from a bulbous corm base (Lavin in Lesica 2012), the bases clustered atop short thick rhizomes (Hitchcock et al. 1969).

Leaves: Sheaths smooth to slightly rough from short, thick hairs, the sheath completely encircling the stem for most of its length (Cronquist et al. 1977); ligules 2–6 mm in length (Lavin in Lesica 2012), strongly lacerate; blades plane to involute (Cronquist et al. 1977), the lower surface minutely roughened and the upper side hairy (FNA 2007), 2–5 mm in width (Lavin in Lesica 2012)

Inflorescence: A narrow panicle or raceme 10–30 cm long, the pedicels stiff, erect, mostly bearing 1 or 2 spikelets (Lavin in Lesica 2012).

(Lavin's contribution adapted from Lavin in Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX.)

Flowering late May-August (Cronquist et al. 1977).

Diagnostic Characteristics
Melica bulbosa and M. spectabilis appear similar and sometimes have spikelets ending in clusters of sterile florets. However, the glumes of M. spectabilis are mostly < 1/2 the length of the spikelets. M. bulbosa’s glumes are 1/2 to 2/3 as long or even equaling the spikelets (Lavin in Lesica 2012). M. bulbosa also has purplish bands concentrated primarily near the tips of its spikelets. In M. spectabilis, the bands are more evenly spaced (FNA 2007).

(Lavin's contribution adapted from Lavin in Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX.)

Species Range

Range Comments
Largely throughout and confined to the western half of North America (FNA 2007), including CO, WY and MT, west to CA and BC, staying mostly east of the Cascade peaks (Hitchcock et al. 1969).

Observations in Montana Natural Heritage Program Database
Number of Observations: 117

(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)

Montane to subalpine elevations on sagebrush inclines (Cronquist et al. 1977), dry meadows, rocky slopes and open understory (Lavin in Lesica 2012).

(Lavin's contribution adapted from Lavin in Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX.)

Reproductive Characteristics
Spikelets: 12–20 mm in length (Lavin in Lesica 2012), distantly spaced or overlapping (Hitchcock et al. 1969), jointed above the glumes and between the florets; glumes ovate, slightly rough with nerves scabrous occasionally, the first glume (5)6-8(9) mm in length and (1-)3-(4)-nerved, the second glume (6.5)7-9(11) mm in length and 5-(7)-nerved; lemmas (6)8-9.5(12) mm in length and (5-)9- to 11-(15)-nerved, rounded or broadly pointed, slightly rough, 4 to 7 per spikelet, awnless; paleas a little shorter than the lemmas (FNA 2007); anthers 2.5-3.5 mm in length (Cronquist et al. 1977).

(Lavin's contribution adapted from Lavin in Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX.)

  • Literature Cited AboveLegend:   View Online Publication
    • Cronquist, A., A. H. Holmgren, N. H. Holmgren, J. L. Reveal, and P. K. Holmgren. 1977. Intermountain flora: Vascular Plants of the Intermountain West, U.S.A. Volume 6: The Monocotyledons. New York, NY: Columbia University Press. 584 pp.
    • Flora of North America Editorial Committee, eds. 2007. Flora of North America North of Mexico. Volume 24. Magnoliophyta: Commelinidae, Part 1. Oxford University Press, Inc., NY. xxxiii + 911 pp.
    • Hitchcock, C. L., A. Cronquist, M. Ownbey, and J. W. Thompson. 1969. Vascular Plants of the Pacific Northwest. Part I: Vascular Cryptogams, Gymnosperms and Monocotyledons. Seattle, WA: University of Washington Press. 914 pp.
    • 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.
  • Additional ReferencesLegend:   View Online Publication
    Do you know of a citation we're missing?
    • Flora of North America Editorial Committee. 2007. Flora of North America North of Mexico. Vol. 24. Magnoliophyta: Commelinidae (in part): Poaceae, part 1. Oxford Univ. Press, New York. xxviii + 911 pp.
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Citation for data on this website:
Oniongrass — Melica bulbosa.  Montana Field Guide.  .  Retrieved on , from