Taxonomic name: Sagittaria sagittifolia L.
Synonyms: Sagittaria sagittifolia var. edulis Siebold ex Miq. , Sagittaria sagittifolia var. leucopetala Miq. , Sagittaria sinensis Sims , Sagittaria trifolia L., Sagittaria trifolia var. edulis (Siebold ex Miq.) , Sagittaria trifolia var. sinensis (Sims) Makino , Sagittaria japonica (Hort.)
Common names: arrowhead, chieh ku, chien tao ts'ao, espadana (Portuguese), flecha de agua (Spanish), flèche d'eau (French), giant arrowhead, Hawaii arrowhead, old world arrowhead, pai ti li, Pfeilkraut (German), pijlkruid, saeta de agua (Spanish), sagitária (Portuguese), shui p'Ing, suokiu, t'zu ku, wapatoo, yen wei ts'ao
Organism type: aquatic plant
Sagittaria sagittifolia is a very hardy aquatic plant that has become a general nuisance in the crops' irrigation systems, drains and waterways around the globe.
Sagittaria sagittifolia is a herbaceous aquatic perennial that reaches sizes of 1m by 0.5m . It is a hardy species that is not frost tender. The leaves are borne on triangular stalks that vary in length with the depth of the water in which the plant is growing. They do not lie on the water but stand boldly above it. They are large and arrow-shaped and very glossy. The early, submerged leaves are ribbon like. The flower-stem rises directly from the root and bears several rings of buds and blossoms, three in each ring or whorl, and each flower composed of three outer sepals and three large, pure white petals, with a purple blotch at their base. The upper flowers are stamen bearing; the lower ones generally contain the seed vessels only. S. sagittifolia's tubers are walnut sized and grow just below the mud surface, produced on creeping runners (Grieve, 2005; National Plant Pest Accord, 2001; and Plants for a Future, 2000).
agricultural areas, water courses
Sagittaria sagittifolia can inhabit ponds, canals and slow flowing water on muddy sub-strata in water up to 45cm deep, in acid or calcareous conditions (Plants for a Future, 2000). Scher (UNDATED) adds that S. sagittifolia can be found in Sub-arctic to tropical environments, in quiet, shallow, standing waters, including swamps, reservoirs, rice paddies, river banks, bays.
The Nature Conservancy (2005) explains that S. sagittifolia is a general nuisance in the crops' irrigation systems, drains and waterways of more than 50 countries. This invasive potential stems from its remarkable ability to adapt, both in form and physiology to a variety of habitats.
Plants for a Future (2000) offers a variety of uses both edible and medicinal for S. sagittifolia . The leaves and roots of S. sagittifolia are edible. The root can be cooked and is apparently excellent when roasted and likened to potatoes. The tubers are starchy with a distinct flavour, but should not be eaten raw. The leaves and young stems can also be cooked but are apparently somewhat acrid. The plant also has medicinal properties as an antiscorbutic; diuretic, and galactofuge but may induce premature birth. The authors post a disclaimer for all edible and medical knowledge: "We are not experts on the medicinal uses of plants and much of the information has been taken from other sources. You should talk to someone who knows what they are on about before using any of these plants. Plants For A Future can not take any responsibility for any adverse effects from the use of plants" (Plants for a Future, 2000).
Native range: Asia and Europe (USDA-GRIN, 2005).
Known introduced range: Australasia-Pacific Region, North America, and South America (NIWA, UNDATED; and Scher, UNDATED).
Local dispersal methods
Natural dispersal (local): Reproduction is by achenes and vegetatively by whole, immature plants and underground tubers (Scher, UNDATED).
Water currents: Seeds float easily and can be carried long distances (Scher, UNDATED).
Reproduction is by achenes and vegetatively by whole, immature plants and underground tubers. Seeds float easily and can be carried long distances (Scher, UNDATED).
North American region: S. sagittifolia flowers in mid-summer, and the seeds ripen through the fall. The flowers are monoecious (individual flowers are either male or female, but both sexes can be found on the same plant) and are pollinated by insects (Plants for a Future, 2000).
Reviewed by: Dr. Surrey Jacobs Principal Research Scientist Royal Botanic Gardens Sydney NSW, Australia
Compiled by: National Biological Information Infrastructure (NBII) & IUCN/SSC Invasive Species Specialist Group (ISSG) with support from the Terrestrial and Freshwater Biodiversity Information System (TFBIS) Programme (Copyright statement)
Last Modified: Wednesday, 29 November 2006