Rhynchospora alba
 
White Beak-Rush

Spikelet Showing Achene

Greenbush Bog, 20 km West of Hudson Bay, SK on Highway #3
27-July-2016

In general, there are one or two achenes in each mature spikelet, each subtended by a scale.  At the base of the spikelet there are a few sterile scales which do not contain an achene.  This spikelet contains two achenes, their subtending scales shown with arrows.  An achene can be seen protruding from one of the fertile scales.

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Alba: Answers to key questions in Budd's Flora leading to this species. 
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uppermost bract about as long as the glomerules; NOT  [uppermost bract much longer than the glomerules]

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glomerules turbinate; NOT [glomerules ovoid or oblong]

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bristles 10-12; NOT [bristles 6]

 

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Rhynchospora: Answers to key questions in Budd's Flora  and Flora of Alberta leading to this genus. 
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culms with bristle-like leaves; NOT [culms leafless, with sheaths usually bladeless]

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spikelets several, terminal and lateral; NOT [spikelet solitary, terminal], NOT [spikelets in simple or compound terminal umbels]

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scales of the spikelets several-ranked, spirally imbricate; NOT [scales of the spikelets 2-ranked]

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scales of the spikelets not keeled

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flowers all perfect, or at least one in each spikelet perfect; NOT [flowers imperfect, plants monoecious or dioecious]

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perianth usually present as bristles; NOT [perianth lacking]

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achenes not enclosed in a perigynium or bract; NOT [achenes enclosed in a perigynium or bract]

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base of the style persistent as a tubercle on top of the achene; NOT [base of the style not persistent, the achene without a tubercle]

 

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Cyperaceae: 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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culms usually solid; NOT culms usually hollow]

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leaves three-ranked; NOT [leaves two-ranked]

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inflorescence NOT [a dense, single, cylindrical spike 8-15 cm long, 1-2.5 cm thick], if a single spike, less than 1 cm thick

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flowers not in globular heads; NOT [flowers in globular heads, the upper ones staminate, the lower ones pistillate]

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flowers solitary in the axil of a single bract (scale); NOT [flowers enclosed in two-ranked bracts with the lowest (glumes) empty]

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perianth reduced to bristles, or scales, or lacking; NOT [perianth reduced to minute lodicules], NOT [perianth present, conspicuous, in two series of 3 segments, often brightly colored]