Allium cernuum
 
Nodding Onion

Inflorescence Back

West Block, Cypress Hills
23-July-2006

Note the spathe, divided into two translucent bracts.

The key to the families in Budd's Flora requires that the flowers of Liliaceae NOT be born in a spathe.  However the umbels in genus Allium arise from a spathe that divides into 1-3 bracts.  These bracts are different from the leaf-like spathes of Iridaceae, and it is this family the flora is trying to separate from Liliaceae with this question.

The key to the families in Budd's Flora also requires that the inflorescences of Liliaceae NOT be subtended by strongly sheathing bracts.  This question is meant to separate Liliaceae from Commelinaceae, the Spiderwort family.  There is only one species in this family found in the Canadian prairies (Tradescantia occidentalis or Western Spiderwort), and it is rare, showy, and cannot be confused with any member of Allium.

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Cernuum:  Answers to key questions in Budd's Flora  and Flora of Alberta leading to this species.  
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outer bulb-coats without fibres, or with parallel fibres, not fibrous-reticulate; NOT [outer bulb-coats fibrous-reticulate]

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leaves flat or channelled; NOT [leaves terete or nearly so]

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leaves NOT hollow

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umbel nodding or drooping; NOT [umbel erect or nearly so]

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inflorescence umbellate; NOT [inflorescence subcapitate]

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flower stalks longer than individual flowers

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ovary crested with 6 flattened or knob-like processes; NOT [ovary crestless]

 

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Allium: Answers to key questions in Budd's Flora and Flora of Alberta leading to this genus. 
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plants with an onion odour

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plants NOT climbing; NOT [plants climbing with tendrils]

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cladodes absent; NOT [cladodes present, being axillary branches with needle-like segments].  Cladodes are flattened green stems which function as the primary photosynthetic organ in lieu of normal leaves.

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leaves green, normal; NOT [leaves reduced to thin, dry scales]

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leaves linear, many times as long as wide; NOT [leaves lanceolate or broader, not more than five times as long as wide]

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flowers usually terminal; NOT axillary

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inflorescence an umbel or head-like cluster; NOT [inflorescence a many-flowered raceme]; NOT [flowers in dense or slender racemes]

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flowers more than 3, often very numerous; NOT [flowers 1-3 (rarely as many as 5)]

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flowers 5-15 mm long; NOT [flowers large, to 25 mm long]

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flowers NOT orange

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fruit dry; NOT [fruit often juicy]

 
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Liliaceae: Answers to key questions in Budd's Flora  leading to this family. 
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plants not aquatic, or if growing in water, most of the plant emersed; NOT [plants aquatic, floating or submerged, with floating leaves or emersed inflorescence]

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leaves NOT sheathing the stem

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inflorescence NOT subtended by strongly sheathing bracts

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flowers NOT borne in a spathe

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flowers regular

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perianth present, conspicuous, in two series of 3 segments, often brightly colored; NOT [perianth absent or inconspicuous]

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perianth usually large; NOT small

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perianth consisting of sepals and petals usually alike; NOT [perianth consisting of 3 green sepals and 3 whitish petals]

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petals NOT deciduous

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stamens 6; NOT 3; NOT [1 or 2]

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ovary superior; NOT inferior