Angled Onion

Allium triquetrum

A declared noxious weed Australia-wide, will you help eat this plant to extermination (in Oz)?

Names

A member of the ever-popular Allium (A.) genus, Allium triquetrum is the Latin botanical moniker given to this menace weed. Its popular name, angled onion, comes from its triangular flower stems and angled leaves. The Latin actually translates into three-corner(ed) garlic, which is another common name. Other names include 'That damned weed' and 'What are all these accursed plants growing?!' (I just made those up for a laugh). In the USA and Canada it can be known as 'snow bells'.

Habitat and Range

Angled onion originates from south-western Europe (Spain-Portugal), north-west Africa (Morocco), Madeira and the Canary Islands, but has been introduced by humans, deliberately or otherwise, to other places in the world such as Britain, New Zealand, Turkey, and some states in the USA (esp. California and Oregon) where it is generally not welcome any longer. This smaller relative of garlic and brown onion is a successful weed, being spread easily by its seeds which exhibit a chemical making them highly attractive to seed-gathering ants, who carry them father than they would otherwise spread by themselves. It has been noticed in Australia, particularly the southern state of Victoria, since the 1920s, but especially since the 1940s. Two preserved specimens from 1909 exist in the State Herbarium of South Australia (Atlas of Living Australia).

Angled onion prefers sheltered, moist underbrush in temperate climes, especially in the south of Australia. It can be found prolifically along roadside culverts, drainage ditches, freshwater creeks, lakes, dams and other places where it can occupy rich, wet soil in mostly-shaded situations. It is especially common in Victoria, but also becoming a nuisance in parts of South Australia, Western Australia, New South Wales and Tasmania. Where it grows, it can often become prolific and choke out native species, hence the 'noxious' tag it has been given.

Figure 1. Distribution of Allium triquetrum across the continent. Atlas of Living Australia.

Identification

Key Identifying Features

• Slender, chive-like leaves angled in a V shape with a prominent vein behind, 15-40 cm in length

• Grows from a small white bulb, similar to spring onion or garlic.

• Flower stems are triangular (three-cornered), 30-50 cm in length

• Flowers are white, 5-7 petals, 5-7 yellow anther tips with green stripes down the throat

• Leaves and bulbs emit a faint onion or garlic-like odour when crushed

Angled onion is not difficult to identify, although it is probably possible to confuse with some native lilies with similar flowers. Look for a grass-like plant that has leaves angled in a V-shape with a prominent vein at the back. The plants flower prolifically, especially in spring (September-December), and the small, trumpet-shaped flowers are quite distinctive because of their three-cornered stems and green stripes down the throat of each petal. Lastly, the flower stems and leaves all emerge from small, yellow-white bulbs which resemble small scallions; older bulbs start to multiply segments just like garlic does.

Figure 2. Close-up of the V-shaped leaf, demonstrating the prominent back-vein along the length. It could be confused with some grasses if not for its scent when crushed. Avenel, Victoria. © JPM, 2022.

Figure 3. Flowers demonstrating green striping and anthers. Not well illustrated: the triangular flower stem. Apollo Bay, Victoria. © JPM, 2022.

Figure 4. The base of angled onion prior to uprooting looks very much like spring onion. The tri-cornered, fleshy flower stems are a little more apparent here, especially the stem on the right, twisting out to bottom of image from under my fingertips. Avenel, Victoria. © JPM, 2022.

Figure 5. Extracted bulbs, stems and all. Apollo Bay, Victoria. © JPM, 2022.

Figure 6. Bulbs after being washed and de-rooted. I was going to plant them in a pot but my wife did not like them so they were eaten instead. © JPM, 2022.

Culinary Uses

Angled onion is a pleasant plant to eat, raw or cooked. Every part of the plant is edible: leaves, stems, flowers and bulbs. It has a flavour about half-way between onion and garlic, being generally mild and delicate on the palate. Thus, it is suitable as a substitute for spring onion (scallion) for soups, stir fries, savoury pancakes, casseroles and all manner of Asian cuisine where spring onion features regularly. Look for plants that are vibrant, green, erect and when harvesting, please remove the whole thing, bulb, roots, flowers and all.

Figure 7. Korean haemul pajeon, seafood onion pancake, prepared with the angled onions I acquired in Victoria. You'd have thought they were spring onions if I didn't tell you otherwise. © JPM, 2022.

If more Australians, particularly in Victoria, joined in the quest to eat this plant to death, we might have the first edible victory over an invasive weed. Beats introducing cane toads to eat them (they won't).

Medicinal Uses

Scant information is available on this plant in established herbal manuals. It is likely it may have some cross-overs with the medicinal properties of garlic (Allium sativum) and onion (Allium cepa) due to the presence of similar beneficial sulphur compounds (allicin and alliin; see Chevallier, 1996: 56 & 162).

Look-Alikes

Two very similar plants found across Australia are onion weed (Nothoscordum gracile) and the Naples onion (Allium neopolitanum). The differences will be explained in the article on onion weed, but since they are all edible there is little risk associated with misidentification. Note that other continents such as North America, Europe and Asia may have other species of 'onion weed', and the intrepid forager is advised to research carefully any potential look-alikes in their own area.

Further Reading

Atlas of Living Australia, "Allium triquetrum." [LINK]

Chevallier (1996), Medicinal Plants, pp. 56 & 162.

Grubb & Raser-Rowland (2012), Weed Forager's Handbook, pp. 27-30.