Aldrovanda vesiculosa, commonly known as the waterwheel plant, is the
sole extant species in the flowering plant genus
Aldrovanda of the
family Droseraceae. The plant captures small aquatic invertebrates
using traps similar to those of the Venus flytrap. The traps are
arranged in whorls around a central, free-floating stem, giving rise
to the common name. This is one of the few plant species capable of
While the genus
Aldrovanda is now monotypic, up to 19 extinct species
are known in the fossil record. While the species displays a
degree of morphological plasticity between populations, A. vesiculosa
possesses a very low genetic diversity across its entire range.
A. vesiculosa has declined over the last century to only 50 confirmed
extant populations worldwide. These are spread across Europe, Africa,
Asia and Australia.
4 Botanical history
5 Infraspecific taxa
6 See also
8 External links
Aldrovanda vesiculosa is a rootless aquatic plant. Seedlings develop a
short protoroot; however, this fails to develop further and senesces.
The plant consists of floating stems reaching a length of
6–40 cm. The 2–3 mm trap leaves grow in whorls of
5–9 in close succession along the plant's central stem. The actual
traps are held by petioles which hold air sacks that aid in flotation.
One end of the stem continually grows while the other end dies off.
Growth is quite rapid (4–9 mm/day in Japanese populations),
so that in optimal conditions a new whorl is produced once or more
The actual traps consist of two lobes which fold together to form a
snap-trap similar to that of the Venus fly trap, except that it is
smaller and located underwater. These traps, which are twisted so that
the trap openings point outward, are lined on the inside by a fine
coating of trigger hairs, snapping shut in response to contact with
aquatic invertebrates and trapping them. The closing of this trap
takes 10–20 milliseconds, making it one of the fastest
examples of plant movement in the kingdom. This trapping is only
possible in warm conditions (20 °C). Each trap is surrounded
by between four and six 6–8 mm long bristles that prevent
triggering of traps by debris in the water.
The small, solitary white flowers of A. vesiculosa are supported above
the water level by short peduncles which arise from whorl axes. The
flower only opens for a few hours, after which the structure is
brought back beneath the water level for seed production. The seeds
are cryptocotylar: the cotyledons remain hidden within the seed coat
and serve as energy storage for the seedlings. Flowering, however, is
rare in temperate regions and poorly successful in terms of fruit and
Aldrovanda vesiculosa reproduces most often through vegetative
reproduction. In favourable conditions, adult plants will produce an
offshoot every 3–4 cm, resulting in new plants as the tips
continue to grow and the old ends die off and separate. Due to the
rapid growth rate of this species, countless new plants can be
produced in a short period of time in this fashion.
Aldrovanda form turions as a frost survival strategy. At
the onset of winter, the growth tip starts producing highly reduced
non-carnivorous leaves on a severely shortened stem. This results in a
tight bud of protective leaves which, being heavier and having
released flotational gases, breaks off the mother plant and sinks to
the water bottom, where temperatures are stable and warmer. Here it
can withstand temperatures as low as −15 °C (5 °F).
In the wild,
Aldrovanda turions have been observed to have a
relatively low rate of successful sinking. Those nutritious
turions that fail to sink are then grazed by waterfowl or are killed
by the onset of frost. In spring when water temperatures rise above
12–15 °C, turions reduce their density and float to the top of
the water, where they germinate and resume growth. Non-dormant
turion-like organs can also form in response to summer drought.
Aldrovanda vesiculosa is the most widely distributed carnivorous plant
species, native to Europe, Asia, Africa, and Australia.
spread mainly through the movement of waterfowl: plants sticking to
the feet of a bird are transported to the next aquatic destination on
the bird's route. As a result, most
Aldrovanda populations are located
along avian migratory routes. Throughout the last century the species
has become increasingly rare, listed as extinct in an increasingly
large number of countries.
A. vesiculosa prefers clean, shallow, warm standing water with bright
light, low nutrient levels and a slightly acidic pH (around 6). It can
be found floating amongst Juncus, reeds, and even rice.
Herbarium specimens deposited at the Museum National d'Histoire
Naturelle in Paris
Aldrovanda vesiculosa was first mentioned in 1696 by Leonard Plukenet,
based on collections made in India. He named the plant Lenticula
pulustris Indica. The modern botanical name originates from Gaetano
Lorenzo Monti, who described Italian specimens in 1747 and named them
Aldrovandia vesiculosa in honor of the Italian naturalist Ulisse
Carl Linnaeus published his
Species Plantarum in
1753, the "i" was dropped from the name (an apparent orthographic
error) to form the modern binomial.
Aldrovanda vesiculosa var. rubescens A.Cross and L.Adamec (2012)
Aldrovanda vesiculosa var. aquitanica Durieu ex Diels (1906) nom.
Aldrovanda vesiculosa var. australis Darwin (1876) nom. illeg.
Aldrovanda vesiculosa var. duriaei Caspary (1859) nom. illeg.
Aldrovanda vesiculosa var. verticillata (Roxb.) Darwin (1876) nom.
^ Cross, A. 2012.
Aldrovanda vesiculosa. In:
IUCN Red List
of Threatened Species. Version 2012.2. Downloaded on 17 October 2012.
^ "World Checklist of Selected
Plant Families". Retrieved July 31,
^ Huber, H. 1961, Aldrovanda, in Hegi, Illustrierte Flora von
Mitteleuropa ed 2. IV(2a): 18-20. Carl Hanser Verlag, München.
^ Degreef, J.D. 1997, Fossil Aldrovanda, Carnivorous
^ a b c d e f Cross, A. 2012. Aldrovanda, The Waterwheel Plant.
Redfern Natural History Productions, Dorset, UK, 249pp
^ Aston, H.I. 1983,
Aldrovanda vesiculosa L., in Flora of
^ Komiya, S. 1966, A report on the natural habitat of Aldrovanda
vesiculosa found in Hanyu City. Amatores Herb. (Kobe, Japan) 27: 5-13.
^ Ashida, J. 1934, Studies on the leaf movement of Aldrovanda
vesiculosa L. I. Process and mechanism of the movement. Mem. Coll.
Sci. Univ. Kyoto Ser. B 9: 141-244.
^ Ashida, J. 1935, Studies on the leaf movement of Aldrovanda
vesiculosa L. II. Effect of mechanical, electrical, thermal, osmotic
and chemical influences. Mem. Coll. Sci. Univ. Kyoto Ser. B 11:
^ Diels, L. 1906, Droseraceae, in Das Pflanzenreich 26 (IV, 112):
^ a b Breckpot, Christian (1997). "
Aldrovanda vesiculosa: Description,
Distribution, Ecology and Cultivation". Carnivorous
^ a b c d L. Adamec: Turion overwintering of aquatic carnivorous
Carnivorous plant newsletter. Arboretum, Fullerton Ca
^ Monti, G. De Aldrovandia nova herba palustris genere. De Bononiensi
Scientiarum et Artium Instituto atque Academia commentarii. v. 2 pt.3,
^ Duval-Jouve, 1861, Bull. Soc. Bot. France 8:518-519.
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