Arethusa bulbosa
 
Dragon's-Mouth

Flower Side, Both Lateral Sepals Removed

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

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Arethusa: Answers to key questions in Lilies, Irises & Orchids of Saskatchewan by Vernon L. Harms and Anna L. Leighton leading to this genus. The answers are in the order you would normally work through the key. 
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Plants green, with at least some green leaf-blades, these sometimes early withering or late developing; flowering stems green (pale pink to purplish-red in Calypso bulbosa), bearing sheathing bracts in some species; rootstocks not coral-like; capsules spreading to erect (occasionally drooping when old); NOT [Plants non-green saprophytes lacking leaf-blades; flowering stems yellowish to purplish-red or brown (pale greenish-yellow in C. trifid), bearing sheathing bracts; rhizomes rootless, coral-like in their branching; capsules drooping]

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Flowers 1 to 2 per stalk (occasionally more in Cypripedium reginae and C. montanum), large, showy; lip 1 cm long or longer, either inflated or broad and flat; NOT [Flowers 3 or more in a spike-like inflorescence, small, often inconspicuous; lip usually less than 1 cm long, but if longer, neither inflated nor broad and flat]

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Lip broad and flat, not inflated; flower subtended by a pair of minute, scale-like floral bracts; leaf single, emerging during or after flowering from upper sheathing bract on stem, linear, grass-like, 2-4 mm wide, folded lengthwise; NOT [Lip inflated, a slipper-like or sac-like pouch; flower subtended by a single, large, usually leaf-shaped floral bract; leaves usually 2 or more, present at flowering-time, (in Calypso bulbosa the broad, basal leaf that is produced the previous fall, may or may not be present at flowering time)]

 

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Orchidaceae: Answers to key questions in Budd's Flora  leading to this family. 
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plants NOT aquatic

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flowers irregular; NOT [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, consisting of sepals and petals usually alike, variously colored; NOT [perianth small, consisting of 3 green sepals and 3 whitish petals]

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petals NOT deciduous

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