Eurasian watermilfoil

Names and Synonyms

Common Names

• Eurasian spiked water-milfoil
• Eurasian water-milfoil
• Spiked Water Milfoil
• Spiked Water-Milfoil
• Spiked water-millfoil
• Eurasian Water Milfoil
• spike water-milfoil

Scientific Names

Accepted name

Synonyms

• Myriophyllum spicatum var. minus
• Myriophyllum spicatum var. baicalense
• Myriophyllum pusillum
• Myriophyllum spicatum var. majus
• Myriophyllum verticillatum subsp. spicatum

Regional and Traditional Names

Sources: Wikidata, Catalogue of Life

Taxonomical Classification

This plant belongs to the kingdom Plantae and is classified within the phylum Streptophyta and class Equisetopsida. Following its descent through the subclass Magnoliidae and order Saxifragales, it is a member of the family Haloragaceae. It is specifically identified under the genus Myriophyllum as the species Myriophyllum spicatum.

Sources: The World Checklist of Vascular Plants (WCVP)

Distribution

This plant, Myriophyllum spicatum, exhibits a specific geographical distribution across several regions of Northern Europe. It can be found growing within the natural landscapes of Denmark. The species is also documented across the coastal and inland waters of Finland. Furthermore, its presence extends to the islands of Great Britain and Ireland. Finally, the plant is a known component of the aquatic flora in Norway.

Sources: The World Checklist of Vascular Plants (WCVP)

Botanical Identification

Ecology

The ecology of Myriophyllum spicatum is defined by its preference for aquatic and semi-aquatic environments, specifically thriving in habitats such as brackish water, rivers, and swamps. This species exhibits a remarkable vertical distribution across varying altitudes, spanning an elevational range from 0 m AMSL to a maximum of 4500 m AMSL. This wide altitudinal tolerance allows it to colonize a diverse array of hydrological systems, ranging from lowland coastal marshes to high-altitude freshwater bodies.

Elevational range max:

4500 m AMSL

Elevational range min:

0 m AMSL

Habitat :

brackish water, rivers, swamps

Life history

The life history of Myriophyllum spicatum is characterized by its status as a perennial species, allowing it to persist in its environment over multiple growing seasons. Functioning primarily as a hydrophyte, this aquatic plant is specialized for life in submerged or floating environments, though it also exhibits characteristics of a cryptophyte, utilizing protected structures to endure varying seasonal conditions. Throughout its life cycle, the plant maintains an evergreen nature, retaining its foliage to facilitate continuous photosynthetic activity within its aquatic habitat.

Deciduousness :

evergreen

Life form :

hydrophyte

Life form :

cryptophyte

Lifecycle :

perennial

Morphology

The morphology of Myriophyllum spicatum is characterized by a versatile growth form, manifesting as both a herb and a forb. This species exhibits significant plasticity in its stature, with plant heights ranging from a minimum of 0.3 m to a maximum of 25 m, maintaining an average height of approximately 9.25 m. Structurally, the plant is non-woody and functions as a self-supporting organism rather than a liana or vine, though it can be categorized as self-supporting in its climbing capacity. The shoot length is notably variable, with minimum measurements recorded at 4 cm and maximum lengths reaching up to 200 cm. In terms of its ecological habit, the plant is primarily terrestrial but demonstrates adaptability across aquatic and semiaquatic environments. It is an independent species that does not function as a parasite, and it is specifically classified as a terrestrial epiphyte.

Aquatic :

aquatic

Climber :

self-supporting

Epiphyte :

terrestrial

Growth form :

herb

Growth form :

forb

Parasite :

independent

Plant height max:

25 m

Plant height mean:

9.25 m

Plant height min:

0.3 m

Shoot length max:

200 cm

Shoot length min:

4 cm

Woodiness :

non-woody

Physiology

The physiology of Myriophyllum spicatum is characterized by a C3 photosynthetic pathway and a non-carnivorous nutritional strategy. Its vegetative architecture features a whorled leaf arrangement, with leaves exhibiting a filiform form. The dimensions of these leaves vary significantly, with a minimum length of 0.3 cm, a mean length of 3.5 cm, and a maximum length reaching 1.7 cm, contributing to a mean leaf size of 0.33825 cm². Furthermore, the plant maintains a mean Specific Leaf Area (SLA) of 249.67 cm²/g, reflecting its physiological adaptations to its aquatic environment.

Carnivory :

non-carnivorous

Leaf arrangement :

whorled

Leaf form :

filiform

Leaf length max:

1.7 cm

Leaf length mean:

3.5 cm

Leaf length min:

0.3 cm

Leaf size mean:

0.33825 cm²

Photosynthetic pathway :

C3

Specific Leaf Area (SLA) mean:

249.67 cm²/g

Reproduction

The reproduction of Myriophyllum spicatum is characterized by a sexual reproductive strategy that is monoeciouse, meaning it possesses both male and female reproductive organs on the same plant, though self-fertilization is notably absent. The flowering process occurs within a specific seasonal window, typically starting in June and concluding in September. The inflorescence is structured as a spike, with lengths ranging from a minimum of 0.06 m to a maximum of 0.1 m. The flowers themselves are red in color and quite small, with lengths varying between 0.18 cm and 0.26 cm. Pollination is driven by abiotic mechanisms, specifically through wind. Following successful pollination, the plant develops dry fruits that are minute in size; these fruits measure between 0.2 cm and 0.25 cm in width and 0.2 cm and 0.3 cm in length. The resulting seeds are equally diminutive, with a mean mass of approximately 0.001158 g (ranging from 0.00104 g to 0.00105 g) and a consistent seed volume of 3.3 mm³. Dispersal is achieved through a hydrochorous syndrome, utilizing water to transport the seeds to new locations. Asexual reproduction is absent in this species.

Dispersal syndrome :

hydrochorous

Flower colour :

red

Flower length max:

0.26 cm

Flower length min:

0.18 cm

Flowering time :

Jun

Flowering time :

Sep

Fruit dryness :

dry

Fruit length max:

0.3 cm

Fruit length mean:

0.25 cm

Fruit length min:

0.2 cm

Fruit width max:

0.3 cm

Fruit width min:

0.25 cm

Inflorescence :

spike

Inflorescence length max:

0.1 m

Inflorescence length min:

0.06 m

Pollination syndrome :

wind

Pollination syndrome :

abiotic

Reproduction asexual :

absent

Reproduction sexual :

monoecious

Seed mass max:

0.00105 g

Seed mass mean:

0.001158 g

Seed mass min:

0.00104 g

Seed volume max:

3.3 mm³

Self fertilization :

absent

Sources: Global Inventory of Floras and Traits (GIFT)

Chemicals

Myriophyllum spicatum has 1 reported phytochemicals identified across 0 scientific publications and several other databases. The most consistently reported chemicals include CR.

CR

1. Environmental monitoring and assessment