Common Name: Broadstemmed Onion

General Information

Allium platycaule is a herbaceous, perennial plant producing two leaves 10 - 30cm long and a flowering scape 7 - 25cm tall from an underground bulb. New bulbs are formed on a short rhizome, the plant gradually forming a clump of growth[, ].
The plant is harvested from the wild for local use as a food.

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[].

Botanical References

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Range

South-western N. America - Oregon, California, Nevada

Habitat

Dry flats, screes and slopes in sagebrush scrub; at elevations from 1,200 - 3,000 metres[, ].

Properties

Edibility Rating
Habit	Bulb
Height	0.12 m
Pollinators	Bees, Insects
Cultivation Status	Wild

Cultivation Details

Allium platycaule is a plant of semi-arid regions in southwest N. America, experiencing a hot, dry summer and winters with temperatures that often go below zero. In moister regions in the temperate zone, especially where summers can be wet, the bulb can easily rot. Very well-drained soil might be enough, but plants will often require some sort of protection from the rain, such as a bulb frame.
Prefers a sunny position in a light well-drained soil[].
The bulbs should be planted fairly deeply[]. Most members of this genus are intolerant of competition from other growing plants[].

Edible Uses

Bulb - raw or cooked[, ]. The bulbs are formed in clusters on a rhizome and are about 20 - 35mm in diameter[].

Leaves - raw or cooked. Used as an onion-flavoured relish[].

Flowers - raw. Used as a garnish on salads.

The seed heads can be placed in hot ashes for a few minutes, then the seeds extracted and eaten[].

Medicinal

Although no specific mention of medicinal uses has been seen for this species, members of this genus are in general very healthy additions to the diet. They contain sulphur compounds (which give them their onion flavour) and when added to the diet on a regular basis they help reduce blood cholesterol levels, act as a tonic to the digestive system and also tonify the circulatory system[].

Agroforestry Uses:

Allium species usually grow well with most plants, especially roses, carrots, beet and chamomile, but they inhibit the growth of legumes[, , ]. They are, in general, bad companions for alfalfa - each species negatively affecting the other[].
Members of this genus are rarely if ever troubled by browsing deer[].

Other Uses

Although no specific mention has been seen for this species, the juice of most species in this genus (especially those with a strong onion or garlic smell) can be used as a moth repellent[].
The whole plant is said to repel insects and moles[].

Propagation

Seed - sow spring in a cold frame. Prick out the seedlings into individual pots when they are large enough to handle - if you want to produce clumps more quickly then put three plants in each pot. Grow them on in the greenhouse for at least their first winter and plant them out into their permanent positions in spring once they are growing vigorously and are large enough.
Division in spring. The plants divide successfully at any time in the growing season, pot up the divisions in a cold frame or greenhouse until they are growing well and then plant them out into their permanent positions.