Northern Ontario Plant Database
Arethusa bulbosa L.
En: dragon's mouth, swamp pink
Orchidaceae (Orchid Family)
General: A perennial forb, to 40 cm tall, growing from a bulbous corm loosely attached to the substrate. Often occurring with Calopogon tuberosus (swamp pink) and Pogonia ophioglossoides (rose pogonia) in Sphagnum bogs and fens. Arethusa bulbosa is the earliest of these fen orchids to bloom. One of the most beautiful of our native orchids, it was named for the Greek nymph Arethusa.
Leaves: Single, basal, sheathing, linear to lanceolate, to 23 mm in length and 12 mm in width. The solitary grass-like leaf develops after the blooming period (anthesis) and is subtended by 2-3 bladeless sheaths.
Flowers: Solitary (rarely 2), various shades of pink to magenta, rarely white or bluish. Tepals are erect to slightly arched and narrowly oblanceolate, 2–5 cm in length and 0.3–1 cm in width. The pinkish white lip is oblong to obovate, arched to reflexed, freckled with pink to magenta blotches, and shallowly lobed, with 3–5 crests of yellow to white fleshy bristles running lengthwise along the centre. The blooming period is generally June to July.
Fruit: An ellipsoid to ovoid capsule, erect, grayish brown, to 4 cm in length. The minute seeds are released by late September.
Habitat and Range: Sphagnum bogs, calcareous treed to open fens, and coniferous swamps. Arethusa bulbosa is native to northeastern North America and distributed widely throughout Ontario, to 53EN.
Internet Images: The Arethusa bulbosa page from Orchids of Wisconsin.
– written by Derek Goertz
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