Chinese Arrowroot, Threeleaf arrowhead
Sagittaria trifolia
Family: Alismataceae
What it is like
Sagittaria trifolia is a PERENNIAL growing to 1 m (3ft 3in). See above for USDA hardiness. It is hardy to UK zone 7. It is in flower from July to August. 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 can grow in semi-shade (light woodland) or no shade. It prefers wet soil and can grow in water.
Height (m): 1
Where it is found
Ponds, lakes, marshes, paddy fields and channels.
Southern European Russia, through temperate Asia to tropical southeastern Asia in Malaysia, Indonesia and the Philippines.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 4
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: 2
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.
Skin: Plants used in miscellaneous treatments for the skin.
Other
Rating: 0
Food Forest: Plants for Edible Forest Gardens and Food Forests.
How it is grown
There is considerable confusion over the correct name of this species. We have adopted the approach followed in the Flora of China which seperates this species from S. sagittifolia and then divides it into two varieties, S. trifolia var trifolia - the wild form with smaller tubers, and S. trifolia var sinensis - a cultivated form with larger tubers. Found from the temperate zone through to the tropics. It grows best in areas where annual daytime temperatures are within the range 16 - 24°c, but can tolerate 12 - 28°c. When dormant, the plant can survive temperatures down to about -10°c, but young growth can be severely damaged at 0°c. It prefers a mean annual rainfall in the range 00 - 1,200mm, but tolerates 600 - 1,500mm. A pond or bog garden plant, it requires a moist or wet loamy soil in a sunny position. Grows best in a rich soil. Prefers shallow, still or slowly flowing water up to 30 - 60cm deep. Prefers a pH in the range 6 - 7.5, tolerating 5.5 - 8.2. The plant requires at least a six month growing season in order to produce a crop. Average yields can be 12 - 15 tonnes per hectare. A polymorphic species, the sub-species S. trifolia leucopetala is the form extensively cultivated for its edible tubers in China and other parts of Asia.
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:
Habit: Perennial
Hardiness: 10-12
Growth:
Soil: Light (sandy), medium, heavy (clay)
Shade: Semi-shade, no shade
Moisture: Wet, water