Myriophyllum alterniflorum

Tracheophyta MagnoliopsidaHaloragaceaeMyriophyllumMyriophyllum alterniflorum


This submerged aquatic perennial occurs in both standing and flowing waters, including rapidly flowing, peaty streams and rivers in which few other macrophytes grow. In Scotland and Ireland it occurs in a wide range of habitats (including, occasionally, highly calcareous sites) but in S.E. England it is confined to acidic, mesotrophic or oligotrophic waters. 0-780 m (Lochan an Tairbh-uisge, Mid Perth).



World Distribution

Suboceanic Boreo-temperate element; also in N. America.

Broad Habitats

Light (Ellenberg): 7

Moisture (Ellenberg): 12

Reaction (Ellenberg): 5

Nitrogen (Ellenberg): 3


Salt Tolerance (Ellenberg): 0

January Mean Temperature (Celsius): 3.2

July Mean Temperature (Celsius): 13.8

Annual Precipitation (mm): 1299

Length: 120

Perennation - primary


Life Form - primary

Perennial hydrophyte (perennial water plant)



Clonality - primary

Irregularly fragmenting (mainly water plants)

Distribution information

Count of 10km squares in Great Britain: 1390

Count of 10km squares in Ireland: 327

Count of 10km squares in the Channel Isles: 3

Atlas Change Index: 1

Weighted Changed Factor: -5

Weighted Change Factor Confidence (90%)


Distribution information

JNCC Designations


PLANTATT - Attributes of British and Irish plants. (.zip 1455KB) This dataset was compiled and published in 2004, and last updated in November 2008. Download includes an Excel spreadsheet of the attributes, and a PDF explaining the background and nomenclature. Note that the PDF version is the booklet as published, whereas the Excel spreadsheet incorporates subsequent corrections. A hardcopy can be purchased from the Centre for Ecology and Hydrology.

Atlas text references

Atlas (150b)
Hultén E, Fries M
1986.  Atlas of north European vascular plants north of the Tropic of Cancer. 3 vols.
Meusel H, Jäger E, Rauschert S, Weinert E
1978.  Vergleichende Chorologie der zentraleuropäischen Flora. Volume 2. 2 vols.
Preston CD, Croft JM
1997.  Aquatic plants in Britain and Ireland.