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Myriophyllum alterniflorum Dc.

Slender water-milfoil (en), Myriophylle à fleurs alternes (fr), Myriophylle à feuilles alternes (fr)

Species

Angiosperms > Saxifragales > Haloragaceae > Myriophyllum

Characteristics

Plants mostly monoecious, rarely with bisexual flowers. Perennating turions absent. Stem few branched, 50-100 cm, sparsely brown oval warty, densely leafy, shoot tips knoblike with crowded leaves; internodes 5-10 mm. Submerged leaves 4-or 5-whorled, pectinate, broadly lanceolate in outline, 1-4 × 0.5-1.2 cm; segments in 8-10 pairs, filiform, 0.5-1.5 cm. Inflorescence a terminal spike, nodding before flowering, to 3-7(-12) cm; bracts ovate or linear, margin entire to serrate. Male flowers alternate; bracteoles shorter than flower; calyx campanulate, ca. 0.3 mm, apex 3-toothed; petals yellow, red streaked, oblong-obovate, 1.5-2 mm, 5-6 × as long as calyx; stamens 8. Female flowers opposite or whorled; bracteoles longer than flowers; calyx campanulate, 0.7-1 mm, apex 3-toothed. Fruit 4-loculed, subcylindric, 1.5-2 × ca. 1.5 mm; mericarps sparsely verrucose. 2n = 14. Fl. and fr. Apr-Sep.
More
Stems very slender; no turions; most internodes under 1 cm; lvs whorled, to 1(–3) cm, often shorter than the internodes; spikes emersed, 2–5 cm; bracts mostly alternate, lance-linear, entire or minutely callous-serrulate, shorter than or about equaling the fls, or the very lowest pinnatisect and exceeding the fls; mericarps 1.5 mm, truncate, rounded on the back and at base, minutely granular-roughened; 2n=14. Greenl. to Nf., Mass., N.Y., and Ont.; Europe.
Life form perennial
Growth form herb
Growth support aquatic
Foliage retention deciduous
Sexuality monoecy
Pollination anemogamy
Spread hydrochory
Mature width (meter) -
Mature height (meter) 0.5 - 1.0
Root system creeping-root rhizome
Rooting depth (meter) -
Root diameter (meter) -
Flower color
Blooming months
JanFebMar
AprMayJun
JulAugSep
OctNovDec
Fruit color -
Fruiting months
JanFebMar
AprMayJun
JulAugSep
OctNovDec
Nitrogen fixer -
Photosynthetic pathway c3

Environment

Light 7-9
Soil humidity 10-12
Soil texture 3-4
Soil acidity -
Soil nutriment -
Hardiness (USDA) 5-8

Usage

Uses -
Edible -
Therapeutic use -
Human toxicity -
Animal toxicity -

Cultivation

Can be grown by cuttings.
Mode cuttings
Germination duration (days) -
Germination temperacture (C°) -
Germination luminosity -
Germination treatment -
Minimum temperature (C°) -23
Optimum temperature (C°) -
Size -
Vigor -
Productivity -

Images

Habit

Myriophyllum alterniflorum habit picture by Ruiz de Almirón Lanz (cc-by-sa)

Leaf

Myriophyllum alterniflorum leaf picture by Ruiz de Almirón Lanz (cc-by-sa)

Distribution

Myriophyllum alterniflorum world distribution map, present in Belgium, Canada, Switzerland, China, Czech Republic, Germany, Denmark, Algeria, Spain, Estonia, Finland, France, United Kingdom of Great Britain and Northern Ireland, Greece, Greenland, Iceland, Italy, Lithuania, Luxembourg, Latvia, Morocco, Netherlands, Norway, Poland, Portugal, Russian Federation, Saint Pierre and Miquelon, Sweden, Tunisia, Ukraine, and United States of America

Conservation status

Myriophyllum alterniflorum threat status: Least Concern

Identifiers

LSID urn:lsid:ipni.org:names:430392-1
WFO ID wfo-0000373504
COL ID 458YD
BDTFX ID 43399
INPN ID 109139
Wikipedia (EN) Link
Wikipedia (FR) Link

Synonyms

Myriophyllum montanum Myriophyllum alterniflorum Myriophyllum alterniflorum var. americanum
WorldFloraDB 2024