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Montana Field Guide

Montana Field Guides

Spotted Water-meal - Wolffia brasiliensis
Other Names:  Wolffia punctata

Status Under Review
Native Species

Global Rank: G5
State Rank: S3
(see State Rank Reason below)
C-value: 7


Agency Status
USFWS:
USFS:
BLM:


 

External Links






State Rank Reason (see State Rank above)
A species of limited distribution in Montana, but reported to be locally common in the Bitterroot and Mission Valleys.
 
General Description
Fronds elongate-globular, 0.5–1 mm long, green with minute brown spots (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Diagnostic Characteristics
Montana species of the Duckweed Family are all small, perennial, free-floating, aquatic herbs. In this family the term "leaf" cannot be used because a leaf consists of a stem (petiole) and a blade (Landolt in FNA 2000). Instead the term "frond" is used. Be aware that species can grow in the same place naturally.

Lemna - Duckweed, native
* Fronds: Green above and mostly below.
* Root: 1 per frond, sometimes absent.
* Veins: 1-3 per frond.

Spirodela - Duck-meal, native
* Fronds: Green above and usually purplish below.
* Roots: 2 or more per frond
* Veins: 3 or more per frond.

Wolffia - Water-meal, native
* Fronds: Green to brown; round.
* Root: 0; absent.
* Veins: 0; absent.

Range Comments
Lake and Ravalli counties. Eastern and northwest U.S. to S. America (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
Fresh water of ponds and sloughs in the valley zone.


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.
  • 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 "Spotted Water-meal"
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Citation for data on this website:
Spotted Water-meal — Wolffia brasiliensis.  Montana Field Guide.  .  Retrieved on , from