Allium sphaerocephalon

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Allium sphaerocephalon
Alcala de Henares (RPS 01-06-2024) Allium sphaerocephalon.png
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Order: Asparagales
Family: Amaryllidaceae
Subfamily: Allioideae
Genus: Allium
Subgenus: A. subg. Allium
Species:
A. sphaerocephalon
Binomial name
Allium sphaerocephalon
L.
Synonyms [1]
Species synonymy
  • Allium aegaeumHeldr. & Halácsy
  • Allium aestivumTineo
  • Allium approximatumGren. & Gord.
  • Allium arvense subsp. aestivum(Tineo) Nyman
  • Allium arvense var. tenuiflorumNyman
  • Allium atroviolaceumHornem. ex Steud.
  • Allium borbasiiA.Kern.
  • Allium bosniacumKumm. & Sendtn.
  • Allium cornutumKit.
  • Allium crinitumTausch
  • Allium densiflorumDe Not.
  • Allium descendensL.
  • Allium desegliseiBoreau
  • Allium eminensGren. ex Parl.
  • Allium gherardiiDe Not.
  • Allium lineareTen.
  • Allium loscosiiK.Richt.
  • Allium macrocephalumKit.
  • Allium margaritaceum var. robustumMaire
  • Allium parviflorumL.
  • Allium parviflorumDesv.
  • Allium parvifoliumCrantz
  • Allium purpureumLoscos
  • Allium pygmaeumE.Perrier
  • Allium regnieriMaire
  • Allium rotundum var. bosniacum(Kumm. & Sendtn.) Nyman
  • Allium sardoum var. gherardii(De Not.) Nyman
  • Allium schmidtianumTausch
  • Allium sphaerocephalon var. aegaeum(Heldr. & Halácsy) Hayek
  • Allium sphaerocephalon var. approximatum(Gren. & Gord.) Nyman
  • Allium sphaerocephalon var. bosniacum(Kumm. & Sendtn.) Asch. & Graebn.
  • Allium sphaerocephalon var. crinitum(Tausch) Nyman
  • Allium sphaerocephalon var. descendens(L.) Regel
  • Allium sphaerocephalon subsp. descendens(L.) K.Richt.
  • Allium sphaerocephalon f. prostratumCorill., Figureau & Godeau
  • Allium sphaerocephalon var. purpureumNyman
  • Allium tenuiflorumDelastre
  • Allium veronenseSpreng.
  • Kromon parviflorum(L.) Raf.
  • Porrum crinitum(Tausch) Rchb.
  • Porrum descendens(L.) Rchb.
  • Porrum sphaerocephaluon(L.) Rchb.

Allium sphaerocephalon is a plant species in the Amaryllis family known as round-headed leek, round-headed garlic, ball-head onion, and other variations on these names. Drumstick allium is another common name applied to this species. Some publications use the alternate spelling Allium sphaerocephalum. [2] It is a bulbous herbaceous perennial plant.

Contents

Allium sphaerocephalon is found in the wild across all parts of Europe except in the northern and western countries (Scotland, Ireland, Netherlands, Scandinavia, and the Baltic States). [3] [4] Its native range extends to northern Africa and to western Asia as far east as Iran. [5] It is also reportedly naturalised in New York State in the United States. [6] In England it grows wild only in the Avon Gorge so is known locally as the Bristol onion. [7]

The species is prized by gardeners because of its striking floral display. The spherical "head" (technically an umbel) is borne on a long scape, up to 50 cm in height, usually in July. It can contain hundreds of deep reddish purple flowers. [5]

The specific epithet sphaerocephalon derives from ancient Greek, meaning "spherical head".

This plant has gained the Royal Horticultural Society's Award of Garden Merit. [8]

Description

Allium sphaerocephalon produces egg-shaped bulbs. Small bulblets are present under the outer layer of the stem (making the plant potentially invasive when grown in gardens). Flowers are borne on a scape up to 50 cm in height, in a spherical to egg-shaped umbel, 1–6 cm in diameter, tightly packed with many flowers crowded together. The relatively small size of the umbel relative to the height of the stem makes this one of those described as "drumstick alliums". Individual flowers are reddish-purple and are occasionally replaced by bulbils (again making this a potentially invasive species). [3]

Subspecies and varieties

[1]

Formerly included

[1]

References

  1. 1 2 3 Kew World Checklist of Selected Plant Families
  2. E.g. Mathew, Brian (1978), The Larger Bulbs, London: B.T. Batsford (in association with the Royal Horticultural Society), ISBN   978-0-7134-1246-8
  3. 1 2 Davies, Dilys (1992), Alliums : the ornamental onions, London: B.T. Batsford (in association with the Hardy Plant Society), ISBN   978-0-7134-7030-7 , p. 135
  4. Altervista Flora Italiana, Schede di botanica, Allium sphaerocephalon
  5. 1 2 Missouri Botanical Garden, Gardening Help, Allium sphaerocephalon
  6. Biota of North America Program, Allium sphaerocephalon
  7. "Bristol Onion". Bristol University. Retrieved 2014-10-08.
  8. "RHS Plantfinder - Allium sphaerocephalon". Royal Horticultural Society. 2016. Retrieved 5 January 2018.
  9. 1 2 3 Kew Royal Botanical Garden, London, Allium sphaerocephalon