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Orchidaceae: Platanthera grandiflora (Bigelow) Lindl.
(large purple fringed orchid )

flower There are two purple, fringed, Platanthera orchids in Nova Scotia: P. grandiflora, the large purple fringed orchid, and P. psycodes, the small purple fringed orchid. Both bear flowers on a leafy raceme, the uppermost leaves grading into bracts; flowers are lilac to purple, with 3-parted, coarsely fringed lips with a prominent spur. They are both tall orchids (P. grandiflora 17-120 cm; P. psycodes: 14-101 cm).1 The two species are distinguished from each other by the size of the flower (P. grandiflora: inflorescence 5-9 cm wide and lip 1.8-2.5 cm wide; P. psycodes inflorescence 2.5-4.5 cm wide and lip 1-1.3 cm wide),2 shape of the opening to the spur (oval to round in P. grandiflora and horizontally oriented, rectangular or barbell shaped in P. psycodes), orientation of the anther sacs (diverging downward in P. grandiflora, close and parallel in P. psycodes). Carl Munden3 notes differences in the racemes as well: "The raceme or floral columns of Platanthera psycodes is more densely packed with a larger number of blossoms and usually with a flatter top. The coloring of this plant [P. psycoides] can also be more intense than on the large purple fringed, being at times a rich magenta." Munden comments that P. grandflora begins to flower in mid-July, about 2 weeks earlier than P. psycodes, apparently with little or no overlap. P. grandiflora is known to hybridize with the green fringed orchid, Platanthera lacera1, 3, which in Nova Scotia flowers at roughly the same time and occurs in similar habitats, including wet meadows and along streams. P. grandflora occurs from Ontario east in Canada, and in the eastern U.S. down to Georgia.
Sources | Notes & Refs | Selected Web Resources | Line Drawing

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July 28, 2007 Halifax County: Carol's Corner . Photographer: Heather Drope.
Large purple fringed orchid Large purple fringed orchid

Selected Web Resources

Notes & References

  1. Flora of North America: Platanthera grandiflora FNA Vol. 26 Page 565. [Accessed 9 Dec. 2007]
  2. Zinck, M. 1998. Roland's flora of Nova Scotia. Nova Scotia Museum and Nimbus Publishing, Halifax, Nova Scotia.
  3. 3. Munden, C. 1999. Native orchids of Nova Scotia. A field guide. University College of Cape Breton Press Inc.