Allium fistulosum

Allium fistulosum, the Welsh onion, also commonly called bunching onion, long green onion, Japanese bunching onion, and spring onion, is a species of perennial plant, often considered to be a kind of scallion. The species is very similar in taste and odor to the related common onion, Allium cepa, and hybrids between the two (tree onions) exist. A. fistulosum, however, does not develop bulbs, and its leaves and scapes are hollow (fistulosum means 'hollow'). Larger varieties of A. fistulosum, such as the Japanese negi, resemble the leek, and smaller varieties resemble chives. A. fistulosum can multiply by forming perennial evergreen clumps. It is also grown in a bunch as an ornamental plant.

Description

An onion family plant. A bulb plant but the bulb is indistinct. It grows to 60 cm high and 20 cm wide. The roots are side roots and fibrous. They grow in large clumps. The leaves are rounded in cross section and hollow. They grow to 15-30 cm long by 5-20 mm wide. The bulbs are very small and 4-8 cm long but only 5-25 mm across. The plant produces many side buds which develop as offshoots. Flowers grow on a stalk which comes from underground and there are many flowers on stalks around one head. This hollow stalk is 40-80 cm long. The flowers are yellow and they open from the top of the flower head downwards. There can sometimes be bulbils on the flower head.

Edible Uses

The bulbs can be eaten raw or cooked, delivering a strong onion flavour that works well in salads, as a cooked vegetable, or as a flavouring in cooked dishes. They are typically small — usually 10–25mm in diameter, though occasionally reaching 45mm — and are sometimes used as spring onions. The leaves have a milder onion flavour and can be eaten raw in salads or cooked as a vegetable. They are often available throughout winter in mild weather and contain approximately 1.4% protein, 0.3% fat, 4.6% carbohydrate, and 0.8% ash, along with some vitamin B1 and moderate levels of vitamin C. The flowers are also edible raw and carry a pleasant onion flavour, though they tend to be on the dry side.

Medicinal Uses

The bulb contains an essential oil rich in sulphur compounds and is antibacterial, antiseptic, diaphoretic, diuretic, galactogogue, stomachic, vermifuge, and vulnerary. It is used in the treatment of colds and abdominal coldness and fullness. A tea made from the roots acts as a sedative for children. Including the bulb regularly in the diet helps impede internal parasites. Externally, the bulb can be made into a poultice to draw pus from sores, boils, and abscesses.

Known Hazards

Although no individual reports regarding this species have been seen, there have been cases of poisoning caused by the consumption, in large quantities and by some mammals, of certain members of this genus. Dogs seem to be particularly susceptible.

Distribution

A temperate plant. It prefers a sunny position and a light well drained soil. It prefers a pH in the range 6.5 to 7.5, but it tolerates a pH in the range 4.9 to 7.5. A hardy plant which produces leaves throughout the winter. They are also tolerant of high temperatures and can grow in the tropics. Plants yield better when grown above 1,000 m in the tropics. In PNG it has been recorded from sea level to 2,800 m above sea level. Temperatures above 25°C give less production. It suits hardiness zones 5-9. In Yunnan.

Where It Grows

Africa, Amazon, Andes, Asia, Australia, Brazil, Britain, Cambodia, Cameroon, Canada, Cape Verde, Caucasus, Central Africa, Chad, China, Colombia, Congo DR, Cook Islands, Côte d'Ivoire, Cuba, East Africa, East Timor, Ecuador, Europe, Fiji, Georgia, Guam, Hawaii, India, Indochina, Indonesia, Ivory Coast, Japan, Kenya, Kiribati, Korea, Lithuania, Malaysia, Marshall Islands, Mironesia, Nauru, Nigeria, North America, Pacific, Papua New Guinea, PNG, Philippines, Rotuma, Russia, SE Asia, Serbia, Siberia, Sierra Leone, Slovenia, Solomon Islands, South Africa, Southern Africa, South America, Sri Lanka, Taiwan, Tasmania, Thailand, Timor-Leste, Tuvalu, USA, Vanuatu, Vietnam, West Africa, West Indies, West Timor, Zambia, Zimbabwe,

Cultivation

An easily grown plant, it prefers a sunny position in a light well-drained soil but tolerates most soils including those that are damp and acid. Prefers a pH in the range 6.5 to 7.5, but it tolerates a pH in the range 4.9 to 7.5. A very hardy species, it is related to the cultivated onion (A. cepa) and could be of value in breeding programmes. It is sometimes cultivated in the garden for its edible leaves which can be produced throughout the winter if the weather is not too severe. A very popular cultivated vegetable in the Orient, it probably arose through cultivation from A. altaicum. The oriental forms of this species, known as bunching onions, tend to be hardier and more robust than the welsh onion. There are two basic forms, multi-stem types and single-stem types. The single-stem types divide less freely than the multi-stems. Plants will often retain their leaves even when covered in snow. They are also tolerant of high temperatures and can be grown in the tropics. The plants are often eaten by slugs. The bulbs should be planted fairly deeply. Most members of this genus are intolerant of competition from other growing plants. Grows well with most plants, especially roses, carrots, beet and chamomile, but it inhibits the growth of legumes. This plant is a bad companion for alfalfa, each species negatively affecting the other. Members of this genus are rarely if ever troubled by browsing deer. Alliums are typically harvested in late spring to early summer, when the bulbs mature and the tops begin to yellow. Allium species typically flower in late spring to early summer, depending on the species and local climate conditions. Allium species generally have a moderate growth rate, with bulbs typically taking about 100 to 150 days from planting to harvest, depending on the variety and growing conditions.

Propagation

Sow seed in spring in a greenhouse — germination occurs across a wide temperature range but is faster at higher temperatures. Prick seedlings into individual pots once large enough to handle. Well-grown plants should be ready to plant out by summer; if they are not sufficiently developed, overwinter them in the greenhouse and plant out in late spring. Division is straightforward and can be carried out at almost any time of year, though spring is preferred. Divisions can be planted directly into their permanent positions if needed.

Other Uses

The plant's juice serves as a moth repellent, and the whole plant is said to deter insects and moles. The flowers are rich in nectar and pollen, attracting pollinators such as bees and butterflies. The bulbs, leaves, and flowers provide food for both humans and wildlife, and the leaf litter offers some habitat value. The strong sulphur-based aroma also acts as a natural pest confuser in the garden. This plant is noted for use in food forest systems.

Other Information

It is a commercially cultivated vegetable.

Notes

The leaves contain about 1.4% protein, 0.3% fat, 4.6% carbohydrate, 0.8% ash, some vitamin B1 and moderate levels of vitamin C Root (Dry weight) Water: 0 Calories: 349 Protein: 18.6 Fat: 3.5 Carbohydrate: 70.9 Fibre: 9.3 Ash: Calcium: 640 Phosphorus: 477 Iron: 13 Sodium: 174 Potassium: 2233 Vitamin A: 7326 Thiamine: 0.69999 Riboflavin: 0.93 Niacin: 5.81 Vitamin C: 221. There are about 300-700 Allium species. Most species of Allium are edible (Flora of China). All alliums are edible but they may not all be worth eating! They have also been put in the family Alliaceae. It has 14.5 mg per 100 g dry weight and 7.5 mg fresh weight of alpha-tocopherol (Vitamin E).

Nutrition

Synonyms

Also Known As

Atasuki, Bawang daun, Bawang bakung, Bawang oncang, Bola, Bola di nseki, Buyah, Cebolinha, Ceboule, Chang fa, Chibol, Ch'lakhvi, Ciboule, Cong, Da cong, Daun bawang, Hanh la, Hari piaz, Hom-chin, Hom-ton, Japanese leek, Lunu kolle, Multiplier onion, Ndembi, Negi, Niasibola, Oriental bunching onion, Pa, Quing cong, Scallion, Sibuyas na mura, Stony leek, Tai tsung, Te anian, Ton hom, Ts'ung fa, Welsh onion, Zimska čebula

References (70)

• Ambasta S.P. (Ed.), 2000, The Useful Plants of India. CSIR India. p 28
• Bernal, R., et al, (Eds), 2016, Catalogo de Plantas y Liquenes de Colombia, Volumen 2, Magnoliaceae a Zygophyllaceae. Universidad Nacional de Colombia. p 2495
• Bremness, L., 1994, Herbs. Collins Eyewitness Handbooks. Harper Collins. p 142
• Brown, D., 2002, The Royal Horticultural Society encyclopedia of Herbs and their uses. DK Books. p 113
• Bussman, R. W., et al, 2016, A comparative ethnobotany of Khevsureti, Samtskhe-Javakheti, Tusheti, Svaneti, and Racha-Lechkhumi, Republic of Georgia (Sakartvelo), Caucasus. Journal of Ethnobiology and Ethnomedicine (2016) 12:43

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