Water Lettuce

Names and Synonyms

Common Names

• Nile cabbage
• tropical duckweed
• water cabbage
• water lettuce
• Water-lettuce
• Nile-cabbage
• shellflower
• tropical-duckweed
• water-cabbage
• waterbonnet
• Nile Lettuce

Scientific Names

Accepted name

Synonyms

• Pistia stratiotes var. linguiformis
• Pistia stratiotes var. cuneata
• Pistia schleideniana
• Limnonesis friedrichsthaliana
• Pistia amazonica
• Pistia brasiliensis
• Pistia cumingii
• Pistia gardneri
• Pistia horkeliana
• Pistia leprieuri
• Pistia linguiformis
• Pistia minor
• Pistia natalensis
• Pistia obcordata
• Pistia occidentalis
• Pistia spathulata
• Pistia commutata
• Pistia crispata
• Pistia africana
• Pistia stratiotes var. obcordata
• Apiospermum obcordatum
• Limnonesis commutata
• Pistia stratiotes var. spathulata
• Zala asiatica
• Pistia aegyptiaca
• Pistia aethiopica
• Pistia texensis
• Pistia turpinii
• Pistia weigeltiana

Regional and Traditional Names

Sources: Wikidata, Catalogue of Life

Taxonomical Classification

This plant belongs to the kingdom Plantae and the phylum Streptophyta, falling under the class Equisetopsida and subclass Magnoliidae. Within the order Alismatales and family Araceae, it is classified under the genus Pistia. This specific taxonomic lineage defines the biological identity of the medicinal species Pistia stratiotes.

Sources: The World Checklist of Vascular Plants (WCVP)

Distribution

This plant exhibits a diverse geographical distribution across several regions of the European continent. In Northern Europe, its presence can be documented within the borders of Great Britain. Moving into Middle Europe, the species is commonly found in both Germany and the Netherlands. Its range extends into Southeastern Europe, specifically reaching as far as Italy. Finally, the distribution continues into Eastern Europe, where it is located in Ukraine.

Sources: The World Checklist of Vascular Plants (WCVP)

Botanical Identification

Ecology

The ecology of Pistia stratiotes is fundamentally defined by its strictly aquatic habitat, where it thrives as a free-floating macrophyte. It is distributed across a broad altitudinal gradient, occupying environments ranging from sea level up to a maximum elevation of 2000 m AMSL. On average, the species is most commonly encountered at a mean elevation of approximately 400 m AMSL, though it maintains a versatile ecological presence across various water bodies within its specified vertical range.

Elevational range max:

2000 m AMSL

Elevational range mean:

400 m AMSL

Elevational range min:

0 m AMSL

Habitat :

aquatic

Genetics

The genetics of Pistia stratiotes are characterized by a specific karyotypic configuration, most notably defined by a diploid chromosome number of 28. This chromosomal count serves as a fundamental cytogenetic marker for the species, influencing its reproductive strategies and evolutionary adaptations within aquatic ecosystems. The stability of this genome supports the plant's rapid vegetative propagation, allowing for efficient clonal expansion. Understanding this chromosomal makeup is essential for studying the genetic diversity, polyploidy levels, and potential hybridization events that occur within various populations of the species.

Chromosome number :

28

Life history

The life history of Pistia stratiotes is characterized by a perennial lifecycle, allowing the plant to persist in aquatic environments over multiple growing seasons. Functioning as a helophyte, it maintains a significant presence at the water's surface, utilizing its specialized structure to thrive in lentic habitats. The plant exhibits an evergreen deciduousness, ensuring that its foliage remains functional and productive throughout its active life stages without seasonal leaf shedding. Furthermore, its biological classification includes a cryptophyte life form, reflecting its specialized adaptations for survival within its specific ecological niche.

Deciduousness :

evergreen

Life form :

helophyte

Life form :

cryptophyte

Lifecycle :

perennial

Morphology

The morphology of Pistia stratiotes is characterized by its growth form as a non-woody herb, specifically categorized as a forb. As an aquatic plant, it is independent and does not function as a parasite or an epiphyte, maintaining a terrestrial-like structural independence despite its floating nature. The plant is self-supporting rather than being a climber, liana, or vine. In terms of size, it exhibits a relatively diminutive stature with a plant height that ranges from a minimum of 0.02 m to a maximum of 0.2 m, resulting in an average plant height of approximately 0.125 m.

Aquatic :

aquatic

Climber :

self-supporting

Epiphyte :

terrestrial

Growth form :

herb

Growth form :

forb

Parasite :

independent

Plant height max:

0.2 m

Plant height mean:

0.125 m

Plant height min:

0.02 m

Woodiness :

non-woody

Physiology

The physiology of Pistia stratiotes is characterized by a C3 photosynthetic pathway, which dictates its carbon fixation processes and metabolic efficiency in aquatic environments. The plant exhibits a specialized leaf morphology, featuring obovate-shaped leaves that are arranged in an alternate pattern. These leaves demonstrate significant morphological plasticity, with lengths ranging from a minimum of 2 cm to a maximum of 20 cm, and widths that vary from a minimum of 0.5 cm to a maximum of 15 cm (with a mean width observed around 1.5 cm). Furthermore, the plant does not function as a nitrogen fixer, relying instead on the absorption of nutrients directly from its surrounding aquatic medium to support its physiological growth and development.

Leaf arrangement :

alternate

Leaf form :

obovate

Leaf length max:

20 cm

Leaf length min:

2 cm

Leaf width max:

15 cm

Leaf width mean:

0.5 cm

Leaf width min:

1.5 cm

Nitrogen fixer :

no

Photosynthetic pathway :

C3

Reproduction

The reproduction of Pistia stratiotes involves both sexual and asexual mechanisms, with asexual reproduction being notably present. Sexually, the plant produces bisexual flowers that typically measure between 0.7 cm and 1.2 cm in length, with a maximum width of 0.5 cm. The flowering period is quite extensive and variable, generally spanning from December through September. The pollination process is characterized by abiotic factors and specifically relies on an insect pollination syndrome. In terms of fertilization, self-fertilization is absent. Following successful pollination, the plant develops a berry-type fruit that is indehiscent. Interestingly, the recorded seed mass is 0 g and the number of seeds per fruit is also noted at 0, indicating a unique reproductive profile. Dispersal is primarily achieved through hydrochorous (water) mechanisms, though it can also be anthropochorous (via human activity).

Dehiscence :

indehiscent

Dispersal syndrome :

hydrochorous

Dispersal syndrome :

anthropochorous

Flower length max:

1.2 cm

Flower length min:

0.7 cm

Flower width max:

0.5 cm

Flowering time :

Dec

Flowering time :

Sep

Fruit type :

berry

Pollination syndrome :

insect

Pollination syndrome :

abiotic

Reproduction asexual :

present

Reproduction sexual :

bisexual

Seed mass mean:

0 g

Seeds_per_fruit :

0

Self fertilization :

absent

Sources: Global Inventory of Floras and Traits (GIFT)

Chemicals

Pistia stratiotes has 6 reported phytochemicals identified across 0 scientific publications and several other databases. The most consistently reported chemicals include DPPH radical, Flavonoid, STIGMASTEROL, Stigmasta-4,22-dien-3-one, Stigmasteryl stearate.

DPPH radical

1. Pakistan journal of pharmaceutical sciences

Flavonoid

1. Pakistan journal of pharmaceutical sciences

STIGMASTEROL

1. Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica

Stigmasta-4,22-dien-3-one

1. Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica

Stigmasteryl stearate

1. Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica

palmitic acid

1. Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica

Activities

Pistia stratiotes has 6 reported activities identified across 0 scientific publications and several other databases. The most consistently reported activities include Analgesic, Anthelmintic, Antioxidant, CNS-Depressant, Cytotoxic.

Analgesic

1. Animal models and experimental medicine

Anthelmintic

1. Pakistan journal of pharmaceutical sciences

Antioxidant

1. Pakistan journal of pharmaceutical sciences

CNS-Depressant

1. Animal models and experimental medicine

Cytotoxic

1. Pakistan journal of pharmaceutical sciences

Free-Radical Scavenging

1. Pakistan journal of pharmaceutical sciences

Preparations