Search Field Guide
Advanced Search
MT Gov Logo
Montana Field Guide

Montana Field Guides

Short-pointed Flatsedge - Cyperus acuminatus

Image Copyright and Usage Information
Species of Concern
Native Species

Global Rank: G5
State Rank: S1
(see State Rank Reason below)
State Threat Score: No Known Threats
C-value: 4


Agency Status
USFWS:
USFS:
BLM:


 

External Links

State Rank Reason (see State Rank above)
Rare in Montana, where it is currently known from only 2 collections in the western portion of the state.
 
General Description
Caespitose annual. Stems ascending to erect, 2–5 cm. Leaves basal, 0.5–1 mm wide, U-shaped in cross-section. Inflorescence of hemispheric spikes of sessile spikelets. Spikelets flattened, 3–7 mm long. Scales acuminate, yellowish, 1–2.5 mm long, 3-veined with short ascending tips. Flowers: stamen 1; style 3-branched. Achene narrowly obovate, 3-sided, brown, ca. 1 mm long (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Phenology
Fruit mature in August-September.

Diagnostic Characteristics
Cyperus acuminatus may be distinguished from other annual members of the genus by its globose heads, solitary stamen, and short-pointed (rather than long) flower bracts, which have only 3 veins.

Species Range
Montana Range Range Descriptions

Native
 


Range Comments
Throughout the U.S., Mexico. Known from Cascade and Sanders counties (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

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
Wet soil of pond margins, lakes, and sloughs in the valleys and on the plains.
Predicted Suitable Habitat Model

This species has a Predicted Suitable Habitat Model available.

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

Ecological Systems Associated with this Species


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.
  • Web Search Engines for Articles on "Short-pointed Flatsedge"
Login Logout

Take us with you! PDF icon

Look for this PDF icon as you search and browse.  Click it to build a custom PDF with species shown on that page or for all the species within that taxonomic level.  To create your own list of species, use the PDF Creator tool at the bottom of the Advanced Search page.

Here's some links if you want to download a whole group.

Mammals
Birds
Reptiles
Amphibians
Fish
Invertebrates
Butterflies / Moths
Dragonflies / Damselflies
Ferns and allies
Conifers
Flowering Plants (Dicots)
Flowering Plants (Monocots)
Bryophytes
Lichens
Ecological Systems
Noxious Weeds
Citation for data on this website:
Short-pointed Flatsedge — Cyperus acuminatus.  Montana Field Guide.  .  Retrieved on , from