Arrow Head, Hawaii arrowhead
Sagittaria sagittifolia

Family: Alismataceae

What it is like

Sagittaria sagittifolia (commonly "Arrowhead") is a flowering wetland perennial native to temperate Europe and Asia. It commonly grows in standing, or slow-moving water, 10-50 cm deep. Arrow-shaped leaves are produced at the terminal end of a petiole up to 45 cm long. Edible starchy tubers are found at the base of long, slender roots in the fall, as leaves die back. A similar plant, Sagittaria latifolia, is common to the west coast of North America, and can be used in the same manner.

Sagittaria sagittifolia is a PERENNIAL growing to 1 m (3ft 3in) by 0.5 m (1ft 8in). See above for USDA hardiness. It is hardy to UK zone 7 and is not frost tender. It is in flower from July to August, and the seeds ripen from August to September. The species is monoecious (individual flowers are either male or female, but both sexes can be found on the same plant) and is pollinated by Insects. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It cannot grow in the shade. It prefers wet soil and can grow in water.

Height (m): 1

Where it is found

Ponds, canals and slow flowing water on muddy sub-strata in water up to 45cm deep, in acid or calcareous conditions.

Most of Europe, including Britain, temperate Asia and N. America.

Conservation Status:

Countries/locations it is found in

How it is used

Food

Rating: 5

Root - cooked. Excellent when roasted, the taste is somewhat like potatoes. The tubers are starchy with a distinct flavour. The tubers should not be eaten raw.The skin is rather bitter and is best removed after the tubers have been cooked. Tubers can also be dried and ground into a powder, this powder can be used as a gruel etc or be added to cereal flours and used in making bread.The roots (tubers really) are borne on the ends of slender roots, often 30cm deep in the soil and some distance from the parent plant. The tubers of wild plants are about 15cm in diameter and are best harvested in the late summer as the leaves die down. The dried root contains (per 100g) 364 calories, 17g protein, 1g fat, 76.2g carbohydrate, 3.1g fibre, 5.8g ash, 44mg calcium, 561mg phosphorus, 8.8mg iron, 2,480mg potassium, 0.54mg thiamine, 0.14mg riboflavin, 4.76mg niacin and 17mg ascorbic acid. They contain no carotene. Leaves and young stems - cooked. Somewhat acrid.

Root: includes bulbs, corms, tubers, rhizomes etc.

Medicine

Rating: 1

The plant is antiscorbutic, diuretic. The leaf is used to treat a variety of skin problems. The tuber is discutient, galactofuge and may induce premature birth.

Antiscorbutic: A plant rich in vitamin C that is used to counteract scurvy.

Diuretic: Acts on the kidneys, promoting the flow of urine.

Galactofuge: Stops or reduces the flow of milk in a nursing mother.

Other

Rating: 0

How it is grown

A pond or bog garden plant, it requires a moist or wet loamy soil in a sunny position. Prefers shallow, still or slowly flowing water up to 30 - 60cm deep. Plants are fairly cold tolerant, surviving temperatures down to at least -10°c, though the top growth is damaged once temperatures fall below zero. They grow best in warm weather and require at least a six month growing season in order to produce a crop. A polymorphic species, the sub-species S. sagittifolia leucopetala is extensively cultivated for its edible bulb in China where there are many named varieties.

Propagating it: Seed - best sown as soon as it is ripe in a pot standing in about 5cm of water. Prick out the seedlings into individual pots when they are large enough to handle, and gradually increase the depth of water as the plants grow until it is about 5cm above the top of the pot. Plant out in late spring or early summer of the following year. Division of the tubers in spring or autumn. Easy. Runners potted up at any time in the growing season.

Best place to grow: Pond; Bog Garden;

Habit: Perennial

Hardiness: 6-9

Growth:

Soil: Light (sandy), medium, heavy (clay)

Shade: No shade

Moisture: Wet, water

Things to keep in mind

Its other names

Local names

Synonyms

Sagittaria japonica.