Myriophyllum humile(Raf.) Morong

low watermilfoil

WFO wfo-0000373528 Accepted WFO 2026-06 8 photographs CC0

Plate 1 figs. a–h · 2 observations

This species has been photographed under an open licence only 2 times, so some figures below are different views of the same plant, taken on the same day, rather than different individuals. They are usually different parts of it: the leaf, the flower, the bark.

Myriophyllum humile, photographed by Ian Pfingsten
fig. a Ian Pfingsten, CC0 1.0 / 2022-05-02 / obs. 193871665

Every figure is a research-grade observation under CC0, CC BY or CC BY-SA, rehosted with the photographer’s name, the licence and the observation it came from. Photographs under a NonCommercial licence are excluded from this site and are never stored, which costs us a great many pictures and is not negotiable.

Native range 15 botanical countries

Regions where Myriophyllum humile is native: Connecticut, Delaware, Maine, Maryland, Massachusetts, New Brunswick, New Hampshire, New Jersey, New York, Nova Scotia, Pennsylvania, Québec, Rhode I., Vermont, Virginia ConnecticutMaineMarylandMassachusettsNew BrunswickNew HampshireNew JerseyNew YorkNova ScotiaPennsylvaniaQuébecVermontVirginia DelawareRhode I.
Native distribution of Myriophyllum humile, after Kew’s World Checklist of Vascular Plants. Introduced, extinct and doubtful records are excluded, so this is where the plant is from, not everywhere it now grows. Regions too small to draw at this scale are marked with a dot.
RegionTDWG codeContinent
Connecticut CNT NORTHERN AMERICA
Delaware DEL
Maine MAI
Maryland MRY
Massachusetts MAS
New Brunswick NBR
New Hampshire NWH
New Jersey NWJ
New York NWY
Nova Scotia NSC
Pennsylvania PEN
Québec QUE
Rhode I. RHO
Vermont VER
Virginia VRG

Region boundaries approximated from Natural Earth (public domain) and mapped to TDWG World Geographical Scheme for Recording Plant Distributions (WGSRPD) level-3 botanical countries (Brummitt 2001). Indicative, not the official WGSRPD geometry.

Where it actually grows measured, from 53 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low -12.1 °C -3.2 °C -0.3 °C
Warmest month, mean daily high 20.6 °C 24.4 °C 29.6 °C
Annual rainfall 1,073 mm 1,243 mm 1,536 mm
Rainfall in the driest quarter 229 mm 276 mm 318 mm

It is found where winters bring hard frost. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 53 research-grade observations of Myriophyllum humile that carry a coordinate, and this is the range those places actually span. The 5th and 95th percentiles are used rather than the minimum and maximum, because a single cultivated specimen in a heated conservatory should not widen a tropical plant's range to the Arctic.

This is not a hardiness zone. A USDA zone is the average annual extreme minimum temperature. The figure above is the mean daily minimum of the coldest month, which is a different quantity and is typically far warmer. Reading one as the other would place a plant several zones too warm, so we do not publish a hardiness zone, because we do not have one.

Also published as 11 synonyms

A synonym is not an error. It is a record of botanists disagreeing, in print, about where this plant belongs. Each of these was somebody’s considered answer.

  • Burshia humilis Raf.
  • Myriophyllum ambiguum Nutt.
  • Myriophyllum ambiguum var. capillaceum (Torr.) Torr. & A.Gray
  • Myriophyllum ambiguum var. humile (Raf.) Britton, Sterns & Poggenb.
  • Myriophyllum ambiguum var. limosum Nutt.
  • Myriophyllum ambiguum var. natans DC.
  • Myriophyllum capillaceum Torr.
  • Myriophyllum humile f. capillaceum Fernald
  • Myriophyllum humile f. humile
  • Myriophyllum humile f. natans (DC.) Fernald
  • Myriophyllum procumbens Bigelow

Sourcesevery claim on this page

  1. World Flora Online Plant List. accepted name, authority, classification. CC0. Retrieved 2026-07-12.
  2. iNaturalist. photographs and flowering annotations, CC0 / CC BY / CC BY-SA only. per photograph. Retrieved 2026-06-27.
  3. Wikidata. common name (P1843), joined on the World Flora Online identifier (P7715). CC0. Retrieved 2026-07-13.
  4. Kew, World Checklist of Vascular Plants (WCVP v16). native distribution by TDWG level-3 botanical country, and life form. CC BY 3.0. Retrieved 2026-06-04.

We publish what we can source and we say so when we cannot. This page has no care advice and no toxicity claim, because we do not yet have those from a source we can cite.