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Montana Field Guide

Montana Field Guides

Western Quillwort - Isoetes occidentalis
Other Names:  Isoetes lacustris var. paupercula

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Species of Concern
Native Species

Global Rank: G4G5
State Rank: S1
(see State Rank Reason below)
State Threat Score: No Known Threats
C-value: 9


Agency Status
USFWS:
USFS:
BLM:


 

External Links






State Rank Reason (see State Rank above)
Isoetes occidentalis is known from two locations in northwest Montana. Survey work to identify other locations, document population sizes, and determine threats is greatly needed.
  • Details on Status Ranking and Review
    Western Quillwort (Isoetes occidentalis) Conservation Status Review
    Review Date = 09/22/2018
    View State Conservation Rank Criteria
    Range Extent

    ScoreB - 100-250 sq km (~40-100 sq mi)

    Area of Occupancy

    ScoreB - 2 4-km2 grid cells

    Number of Populations

    ScoreA - 1 - 5

    Threats

    ScoreD - Low

 
General Description
Plants aquatic. Leaves to 20 cm, gradually tapering. Sporangia 3–6 mm long. Megaspores 0.4–0.8 mm wide (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Species Range
Montana Range Range Descriptions

Native
 


Range Comments
Alaska, British Columbia, and California, east to Montana, Wyoming and Colorado.


Observations in Montana Natural Heritage Program Database
Number of Observations: 3

(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
Our one record is from shallow water of a montane lake in Missoula County (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).
Predicted Suitable Habitat Model

This species has a Predicted Suitable Habitat Model available.

To learn how these Models were created see mtnhp.org/models


Threats or Limiting Factors
STATE THREAT SCORE REASON
Threat impact not assigned because threats are not known (MTNHP Threat Assessment 2021).

References
  • 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.
    • MTNHP Threat Assessment. 2021. State Threat Score Assignment and Assessment of Reported Threats from 2006 to 2021 for State-listed Vascular Plants. Botany Program, Montana Natural Heritage Program, Helena, Montana.
  • Additional ReferencesLegend:   View Online Publication
    Do you know of a citation we're missing?
    • Lesica, P., M.T. Lavin, and P.F. Stickney. 2022. Manual of Montana Vascular Plants, Second Edition. Fort Worth, TX: BRIT Press. viii + 779 p.
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Citation for data on this website:
Western Quillwort — Isoetes occidentalis.  Montana Field Guide.  .  Retrieved on , from