M. verticillatum is a robust, perennial plant of clear or slightly turbid, still or slowly flowing calcareous water in lakes, streams, canals and ditches. It occurs over both peaty and inorganic substrates. It flowers and sets seed, and also perennates by specialised turions which are produced in the leaf axils. Lowland.
This species is probably more frequent in the calcareous central plain of Ireland than elsewhere in our area, and there it is probably still under-recorded. The decline in M. verticillatum in S. England began before the 1962 Atlas, and has continued since then.
Circumpolar Temperate element.
Perennation - primary
Life Form - primary
Clonality - primary
Clonality - secondary
Comment on Clonality
Count of 10km squares in Great Britain: 360
Count of 10km squares in Ireland: 130
Count of 10km squares in the Channel Isles: 0
Atlas Change Index: -0.89
Scarce Atlas Account
Myriophyllum verticillatum L.
A submerged aquatic perennial with emergent flowering spikes, M. verticillatum occurs in ponds, ditches and lakes with base-rich water. It is a characteristic component of a still-water community rich in water-lilies and pondweeds. M. verticillatum is moderately tolerant of shade (i.e. turbid water) and occurs in water moderately rich in nutrients. It grows in grazing marshes with M. spicatum, but usually in more lime-rich water than its relative, and is strictly lowland in its distribution.
It is a creeping perennial rooted in the mud. Reproduction is mainly by vegetative means, with broken fragments rooting and by club-shaped turions produced in late summer and autumn.
M. verticillatum has been noted as declining throughout England and Wales, due to poorer water quality and habitat destruction. Open-water habitat has often been either over-deepened and canalised or colonised by tall emergents as the ditch has become redundant.
It is very widespread in Europe, absent only from a few peripheral islands. M. verticillatum is distributed throughout temperate Asia and North Africa, as well as both North and South America.
J. O. Mountford
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.