Alismataceae Common Names:
Dwarf Sagittaria, Dwarf Arrowhead Origin and Habitat:
Naturally occurs in South America and in the eastern United States; the US Department of Agriculture also lists it in Washington state, likely having been introduced. Found in freshwater and brackish water, in slow flowing rivers, streams, lagoons, and ponds. Ideal position in aquarium
Mid-ground. In larger aquaria can also be used in the fore-ground especially near the sides or for effect next to standing bogwood. It can be used as a background plant if planted very thickly as it will then grow taller. Lighting requirements
Moderate. More intense light may bring out reddish leaf apexes. Growth rate
Slow to moderate Minimum Tank Suggestion
5 or 10 gallon. Water parameters for Dwarf Sagittaria
Soft to hard, acidic to basic, optimum temperature 18-28C/64-82F. It should manage in brackish water since it has been found in such habitats. Description
In appearance, this plant bears a close resemblance to the narrow-leaf form of another plant in the same family, the pygmy chain sword (Helanthium tenellum), and in the aquarium the two can easily be confused. The growth habits of both can be influenced by conditions in the aquarium such as light, nutrients, and in the case of Sagittaria in particular the density of the planting. In the writer's (Byron) aquarium containing both species, they appear identical with the only difference being the greater height of S. subulata
The common name "Dwarf" may be somewhat misleading. The plant will normally attain 10-15cm (4-6 inches) in height; planted very close together, the leaves will be much taller, up to 60cm (24 inches) according to Kasselmann (2003) and others, some of whom also mention age and light as factors affecting the plant's height. The writer (Byron) has this plant easily attaining 12-15 inches when thickly planted under moderate light.
Moderate light is sufficient, but the plant does require good nutrients, especially iron but this must be balanced with the other nutrients either in the substrate or added to the water. A small-grain substrate (sand or fine gravel) is best, and this plant once settled will rapidly spread via runners in the same manner as the dwarf chain swords and Vallisneria
species. It may send an inflorescence to the surface and flower, but flowering is more likely to occur with emersed growth.
The Alismataceae is a family of aquatic herbs containing 12 genera with about 80 species that are distributed in the tropical and subtropical regions of both hemispheres. Three genera of interest to aquarists occur in the Neotropics [=tropical regions in the Americas]: Sagittaria, Echinodorus and Helanthium
. The species in these genera are quite similar in appearance, making it difficult for aquarists to differentiate between them. To add to the confusion, even within each species the plants can take on quite different leaf lengths depending upon the conditions in the aquarium. With a few exceptions that grow fully submersed, the plants are amphibious bog plants in their habitat, spending roughly half the year emersed when they flower, and half submersed during the flooded period.
The genus Sagittaria
was erected in 1753 by Carl Linnaeus, the Swedish botanist, physician and zoologist whose classification of all living organisms led directly to the modern system of binomial nomenclature. The name is derived from the Latin sagitta
[= arrow], referring to the arrow shape of the leaves; some species are distinctly arrowhead shaped, giving the genus its common English name "Arrowheads." The plants in this genus are characterized by having sagittate [=shaped like arrowheads] or hastate [triangular shape] leaves and white scapose flowers. The genus contains approximately 30 species or subspecies, most occurring in the Western Hemisphere (from the southern United States through Mexico and Central America and into much of South America) with some natural to Europe and Asia. The tubers of some species were an important food source of starch for the indigenous peoples of North America and Asia, and gave the plant the common name of "duck potato."
The species are all marsh plants, and only a very few have made their way into the aquarium hobby; several are more popular as outdoor pond plants. S. subulata
is the most common in aquaria, and one sometimes sees S. platyphylla
The subject species was originally named in 1753 by Linnaeus who placed it in the genus Alisma
as Alisma subulatum
. In 1871, Buchenau placed it in Sagittaria
and the epithet changed gender to agree with that of the genus name. The species epithet refers to the submersed (subulate) leaves. The plant may be encountered under the name S. natans
but this is a synonym. References:
Kasselmann, Christel (2003), Aquarium Plants
, English translation, Krieger Publishing Company. Contributing Members
The following members have contributed to this profile: Byron