''Allium sphaerocephalon'' is a plant species in the

Amaryllis family The Amaryllidaceae are a family of herbaceous, mainly perennial and bulbous (rarely rhizomatous) flowering plants in the monocot order Asparagales. The family takes its name from the genus ''Amaryllis'' and is commonly known as the amaryllis fami ...

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''. It is a

bulb In botany, a bulb is structurally a short stem with fleshy leaves or leaf basesBell, A.D. 1997. ''Plant form: an illustrated guide to flowering plant morphology''. Oxford University Press, Oxford, U.K. that function as food storage organs duri ...

ous

herbaceous Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition of t ...

perennial plant. ''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 The Baltic states, et, Balti riigid or the Baltic countries is a geopolitical term, which currently is used to group three countries: Estonia, Latvia, and Lithuania. All three countries are members of NATO, the European Union, the Eurozone, ...

). Its native range extends to northern Africa and to western Asia as far east as Iran.Missouri Botanical Garden, Gardening Help, ''Allium sphaerocephalon''
/ref> It is also reportedly naturalised in New York State, US. In England it grows wild only in the Avon Gorge so is known locally as the Bristol onion. The species is prized by gardeners because of its striking floral display. The spherical "

head A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth, each of which aid in various sensory functions such as sight, hearing, smell, and taste. Some very simple animals may ...

" (technically an umbel) is borne on a long scape, up to 50 cm in height, usually in July. It can contain hundreds of deep purple flowers. The

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

''sphaerocephalon'' derives from ancient Greek, meaning "spherical head". This plant has gained the Royal Horticultural Society’s

Award of Garden Merit The Award of Garden Merit (AGM) is a long-established annual award for plants by the British Royal Horticultural Society (RHS). It is based on assessment of the plants' performance under UK growing conditions. History The Award of Garden Merit ...

Description

''Allium sphaerocephalon'' produces egg-shaped bulbs. Small

bulblet In botany, a bulb is structurally a short Plant stem, stem with fleshy leaf, leaves or leaf basesBell, A.D. 1997. ''Plant form: an illustrated guide to flowering plant morphology''. Oxford University Press, Oxford, U.K. that function as food st ...

s are present under the outer layer of the stem (making the plant potentially

invasive Invasive may refer to: *Invasive (medical) procedure *Invasive species *Invasive observation, especially in reference to surveillance *Invasively progressive spread of disease from one organ in the body to another, especially in reference to cancer ...

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)., p. 135

Subspecies and varieties

*''Allium sphaerocephalon'' var. ''aegaeum'' (Heldr. & Halácsy) Hayek - Aegean Islands *''Allium sphaerocephalon'' subsp. ''arvense'' (Guss.) Arcang. - Sicily, Malta, Albania, Greece, Turkey, Cyprus,

Syria Syria ( ar, سُورِيَا or سُورِيَة, translit=Sūriyā), officially the Syrian Arab Republic ( ar, الجمهورية العربية السورية, al-Jumhūrīyah al-ʻArabīyah as-Sūrīyah), is a Western Asian country loc ...

, Lebanon, Egypt, Algeria, Tunisia, MoroccoKew Royal Botanical Garden, London, ''Allium sphaerocephalon''
/ref> *''Allium sphaerocephalon'' subsp. ''laxiflorum'' (Guss.) Giardina & Raimondo - Sicily *''Allium sphaerocephalon'' subsp. ''sphaerocephalon'' - much of Europe plus Morocco,

Canary Islands The Canary Islands (; es, Canarias, ), also known informally as the Canaries, are a Spanish autonomous community and archipelago in the Atlantic Ocean, in Macaronesia. At their closest point to the African mainland, they are west of Morocc ...

, Middle East *''Allium sphaerocephalon'' subsp. ''trachypus'' (Boiss. & Spruner) K.Richt. - Greece and Turkey incl Aegean Islands

Formerly included

* ''Allium sphaerocephalon'' subsp. ''durandoi'', now called '' Allium ebusitanum'' * ''Allium sphaerocephalon'' subsp. ''ebusitanum'', now called '' Allium ebusitanum'' * ''Allium sphaerocephalon'' subsp. ''rollii'', now called '' Allium amethystinum'' * ''Allium sphaerocephalon'' subsp. ''sardoum'', now called ''

Allium guttatum ''Allium guttatum'', spotted garlic, is a species of wild garlic Plant species in the genus ''Allium'' known as wild garlic include the following: *''Allium canadense'', wild onion *'' Allium carinatum'', keeled garlic *'' Allium drummondii'', D ...

'' subsp. ''sardoum'' * ''Allium sphaerocephalon'' var. ''scaberrimum'', now called '' Allium scaberrimum''

References

External links

*
Comprehensive profile for ''Allium sphaerocephalon''
from the websit
MaltaWildPlants.com
{{Taxonbar, from=Q159286 sphaerocephalon Flora of Europe Flora of North Africa Garden plants Plants described in 1753 Taxa named by Carl Linnaeus